Glossary of Technical Theatre Terms – Scenic

ACT CHANGE
A change of either scenery, lighting, costume, props or other technical elements between acts of a play or musical. Theatres with little backstage space may have to reconfigure scenery stored offstage during the interval so that the next act runs smoothly.

ACT DROP
Victorian stretched framed and painted canvas. Used as a visual stimulation during scene changes, and to indicate that there was more to come (the end being indicated by the HOUSE TABS). There are believed to be only two operational today - an original one at Gaiety Theatre, Isle Of Man, and a 1996 reproduction at Her Majesty's Theatre, Ballarat, Victoria, Australia.
Term now used to refer to any front cloth or tabs lowered during intervals. Especially pantomime / musicals. 
In ballet, the act drop permitted pre-interval curtain calls to take place. 
Gaiety Theatre
Her Majesty's Theatre

AMBIENCE
The character or atmosphere of a space. 
In theatrical terms, this applies to the combination of scenic & prop design along with lighting and sound, working together to create a unique atmosphere, where, particularly in immersive theatre, the space becomes one of the characters, which tells its' own story. 
The term also applies to the background sound in a space used for recording, or the soundscape used as a background sound to establish the location. 

ANILINE DYE
A type of deep penetrating natural dye originally made from coal tar. Water-based or alcohol-based dyes are available. As the product will stain anything it comes into contact with, protective gloves and eye protection should be used.

ANTIQUARIANISM
A movement which insisted on historically-accurate scenery and props on stage. The more stylized sliding wing flats were replaced by more detailed box sets including architectural features, props and furniture appropriate to the time period in whcih the show was taking place. Antiquarianism moved into theatres in the late eighteenth century in Europe. 

ARBOR
US equivalent of CRADLE in a counterweight flying system.

ARTIC
Short for Articulated Lorry. Lorries of 40 feet length (or more) are used to transport sets, costume, props and sound & lighting equipment from venue to venue. A number of companies specialise in moving theatrical and musical tours around the country / world.
Known in the USA as a SEMI (short for Semi-Trailer, where a trailer box with a rear axle only is pulled by a tractor unit). 

AUTOCAD
Industry-standard CAD program for architects and designers. WYSIWYG contains a cut-down version of Autocad, along with visualisation tools.

AUTOMATION
1) Facility available on larger sound mixing desks allowing channel muting or even fader moves to be taken under the control of a computer to ensure accurate and repeatable mixing.
2) Describes the method used instead of stage crew for moving bits of set or actors around stages on productions with sufficient budget. See MOUSE, SPADE, DOG, KNIFE.
Scenic Automation on Theatrecrafts.com

AVISTA / A VISTA
A change of setting / scenery unhidden from the audience. This technique is increasingly popular due to modern advances in scenic automation, where entire set changes can be accomplished in seconds.

AXIS
(plural AXES). An individually controllable moving element controlled by a scenic automation or powered flying system. For example, a system controlling three flying pieces will have three axes of automation.

BACK WALL
The rear wall of the stage (part of the building which cannot be moved!). Sometimes a blank brick wall (often painted black) is a good backing to a show, where theatrical masking is not part of the design aesthetic. Such 'bare walls' productions may also have completely exposed lighting rigs, and no traditional masking, even exposing the exit doors from the stage.
For technical reasons, some shows have a constructed back wall which looks like it's the back wall of the theatre, but actually isn't (e.g. Billy Elliot).

BACKCLOTH
See CLOTH.

BACKDROP
Decorative backing to the stage setting.
See CLOTH, FLATS.
Portuguese: Fundo de Palco

BACKFLAP HINGE
Hinge frequently used in Scenic Construction. 
Available as a loose pin hinge, so the two halves can be separated to easily deconstruct scenery. See PIN HINGE.

BACKING
1) Scenic piece which goes behind an opening in the set (window etc.) to hide the technical areas beyond. Also known as a Backing Flat
2) The money invested in a commercial production (by a Backer).

BALUSTER
Vertical shaft found as a component of stairways, parapets, balconies etc. A systerm of balusters plus a handrail forms a banister for a stairway. A group of balusters (which may be wood or stone) plus coping forms a balustrade on a balcony. 

BANDWAGON
A wheeled platform on stage.
Originally, a large wagon that carried the circus band in a circus procession. The term was first popularised by P.T. Barnum. Parade viewers paid a lot of attention to the band wagon, so politicians started to use a band wagon on the campaign trail. The phrase 'to jump on the bandwagon' came to mean anyone who takes advantage of a popular trend to further their own agenda.

BANJO
(US) Horizontal rail along which a curtain runs (also known as a BANJO TRACK).

BASE COAT
An initial coat of paint to provide a solid colour, or to prime the surface and to prepare it for a more detailed paint job. The base coat may be a cheaper type of paint, to prepare the surface for a thinner coat of colour.

BATTENS
1) Timber at the top and bottom of a cloth. A Sandwich batten is used to carry a hanging cloth. It comprises two flat pieces of timber screwed together with the edge of the cloth between them.
2) Timber used for joining flats together for flying.
3) Compartmentalised floodlights set up to allow colour mixing. See also GROUNDROW. Low voltage battens are commonly used as light curtains & for colour washes. Known in the US as a STRIPLIGHT, BORDER LIGHT or X-LIGHTS. 
4) US term interchangable with PIPE for a flying bar.

BEVEL
1) The sloped edge of a piece of wood or metalwork to smooth off the edge and make the piece more attractive. 
2) A tool consisting of two pivoting arms which can be used to duplicate an angle from one object to another. 

BILLY BLOCK
A pulley on a short length of rope used to divert the pull of a working rope, or to suspend a single item in storage.

BISCUIT
A small oval piece of wood used to reinforce a joint between two adjacent pieces of wood without being visible from the outside. A Biscuit Joiner is used to cut crescent-shaped holes in the adjacent pieces, the biscuit is placed in along with wood glue, and the pieces are brought together and held in place until the glue dries. 

BLOCK
1) Part of the flying system of the theatre - the frame in which one or more pulley wheels (sheaves) are mounted.
2) Wooden cuboid box that can be used to sit or stand on in a rehearsal or drama classroom situation. Also known as a Drama Cube or a Rehearsal Cube.

BLOCK PULLEY
A pulley in a frame which forms part of a grid system above a theatre stage, which carries a line to lift an item, either temporarily positioned as required for a show, or as part of a fixed installation. 
Also known as a LOFT BLOCK. 

BLUEPRINT
A layout plan or other technical drawing. Originally blueprints were actually blue, and were reproduced by contact with a light sensitive paper.
Wikipedia entry

BO
A small seat or cradle rigged on a rope over a pulley whereby a technician may be hoisted to work at an otherwise inaccessible position.

BOOK FLAT
Two flats hinged together on the vertical edge, to be free standing, and normally used as a backing for a doorway or window. They should always be 'run' with the hinged edge leading, to prevent them opening up. Book flats are free-standing when angled open, allowing quick setting and compact storage. Booking describes the action of opening or closing a book flat.
Flats - Types and Methods

BORDER
A narrow horizontal masking piece (flattage or cloth), normally of neutral colour (black) to mask the lighting rig and flown scenery from the audience, and to provide an upper limit to the scene. Often used in conjunction with LEGS.
In part of the 20th century, borders were made from asbestos materials, but are now made from fire-retardant cloth (e.g. Wool Serge). 
Spanish: Bambolina

BOSS PLATE
Metal plate fixed to the stage floor into which a bolt can be screwed for fixing scenery.

BOTTLESCREW
(Also Bottle Strainer, Barrel Strainer) Threaded device which is used to tension a wire, or to provide an adjustable link in a cable, to fine-tune the height of flown scenery. (Known in the USA as a Turnbuckle)

BOX SET
Naturalistic setting of a complete room built from flats with only the side nearest the audience (the fourth wall) missing.
A single static box set that represents more than one room is called a COMPOSITE SET (for example if the living room and the kitchen are both on stage permanently). 

BRACE
1) Angled strengthening timber within a flat.
2) (UK) Support for scenery (flattage) on stage
  2a.) Extendible, hooking into a screw eye on the flat and being weighted to the floor (commonly known as a 'Stage Brace')
  2b). French Brace, right-angled non adjustable triangular frame, made from timber, and attached to the flat with pin hinges so it can be folded against the flat for storage. If the flat is remaining in place as part of a box set, the french brace may be screwed or bolted into position. Known in the USA as a Jack.  When hinged, it can be swung flush to the flat for storage or flying.
See also Jack (US for Brace).
Flats - Types and Methods

BRACE WEIGHT
Slotted cast iron weight placed on foot of extendible or French brace to prevent movement. Often referred to as a 'Stage Weight'

BRAKE
1) Fitted to some castors (wheels) mounted under stage trucks (rolling platforms) to hold them in place. 
2) A separate item retro-fitted to a wheeled platform or piece of scenery which holds it in place, usually by lifting it off the stage slightly to stop the wheel contacting the stage. 
Brakes at Flints Theatrical Chandlers

BREAKING DOWN
Treatment given to freshly painted or newly made props, scenery or costume, to make it look either aged, lived-in, or less "new". Often involves spattering with paint to add interest and texture to areas lacking it.
Breaking Down Props and Costumes

BRECHT CURTAIN
A manually-operated curtain hung from a wire stretched across the stage. Used for projection or lighting effects or for a simple concealment. The curtain is usually flat (without fullness) and is hung from simple rings. The curtain height is usually a minimum of 2.4m high, but does not fill the stage height. 

BRICOLAGE
A piece of art (or a set design or prop) made from a variety of otherwise unrelated items.
Wikipedia entry

BRIDGE LIFT
An elevator which raises and lowers sections of the stage floor, usually by electrical or hydraulic means.

BROADWAY FLAT
Also known as a Theatre Flat, or just a Flat!
Theatrical scenery flat where the framing timber is parallel to the surface of the flat.
See also HOLLYWOOD FLAT. 
Flats - Types and Methods

BUILD
1) During lighting plotting, to construct a state from blackout, or to add to an existing state.
2) An increase in light or sound level. See CHECK.
3) A period of set construction ('The Build').

BUMP OUT
See GET-OUT.

BUNRAKU
Style of Japanese puppetry where the puppet operator carries the puppet onstage and is visible throughout the performance. The puppeteers are highly skilled and respected in Japan, and provide the voice as well as the movements for the incredibly detailed puppets.
About Bunraku

CABLE GRIP
A U-shaped clip and saddle used for terminating wire rope. Also known as a Bulldog, Dog Grip or Wire Rope Clip.

CAD
Computer-Aided Design. Using a computer to help with 2D plans and drawings, or increasingly for 3D visualisation of how a set will look, and how lighting will affect it. See also WYSIWYG.

CASTORS
The wheels on a TRUCK or underneath a REVOLVE.
Swivel castors can rotate 360 degrees allowing the truck to move in any direction. 
Braked castors can be locked to prevent any movement or to lock the direction of travel.
Fixed castors do not rotate and only allow the truck to move in one direction (these should be used for a revolving stage).
Castors on the Flints websitey

CENTRE LINE
Imaginary line running down the stage through the exact centre of the proscenium opening. Marked as CL on stage plans. Normally marked on the stage floor and used as a reference when marking out or assembling a set. A chalked snap line can be used to mark the line in the rehearsal room and on stage.
Known in the US as CENTER LINE.
House Centre / House Center is the centre line of the auditorium (which is usually the same as that of the stage).
See also SETTING LINE.

CHAIN HOIST
Manually operated or electrically driven hoist for lifting scenery and lighting equipment. The chain hoists are rigged to fixed points in the venue. Commonly used to lift lighting truss into position for touring shows or concerts.

CHAIN POCKET
Fabric pocket along the width of the bottom of a cloth or tab holding a chain which weighs the bottom of the cloth down.

CHARIOT AND POLE
Forerunner of the modern mouse and stage method of stage automation. Method of scene changing developed in 1641 by Giacomo Torelli, consisting of slots in the stage floor which supported uprights (known as poles) on which flats were mounted. The poles were attached below stage level to chariots, mounted on casters which run in tracks across the stage. The chariots were connected to ropes via pulleys enabling all flats to be changed via a single winch. 

CHEEK WALL
Side wall running up the edge of a set of stairs / treads, perpendicular to the risers. 

CHIAROSCURO
(n.) In Lighting or Scenic design (and the Art world), Chiaroscuro means the use of contrasts of light and shade, especially in order to enhance the depiction of character and for general dramatic effect. Many painters are said to be masters of Chiaroscuro (especially Rembrandt, Caravaggio etc.) From the Italian words chiaro 'clear, bright' and oscuro 'dark'. From the Random House Word of the Day website.

CLEAR DOPE
Used in finishing prop/mask/model constructions using tissue paper. Originally a nitrocellulose (nitrate) dope used to shrink / seal and strenghthen lightweight tissue material in model-making or prop / mask / puppet construction. Nowadays, a diluted white glue is used instead as it's highly flammable. 

COFFIN LOCK
A slang term for a blind panel connector (also called a Butt-Joint Fastener) often used in the entertainment industry to join together stage decks or scenery in a butt joint or cabinet and lid locks on road cases. These are typically two part connectors (male and female) that draw together and lock.

COKE THE STAGE
One possible solution to a slippery wooden stage surface is to apply a watered-down solution of Coca-Cola with a mop. A small bottle (500ml / 20fl.oz) should be poured into a mop bucket, which is then filled with water. 
Commercial products (such as SlipNoMore) will have a more measured effect, and will be more likely to last longer, and be less attractive to critters. 
A better long-term plan is to use a vinyl dance floor on top of the wooden surface, or to clad the stage with hardboard/Masonite and then paint it.
SlipNoMore

COLOUR THEORY
The science behind the way colour works can help lighting, costume and set designers to make their work as vibrant (or dull) as the play requires. See the link below for information. 
Choosing and Using Colour

CONSTRUCTION (DESIGN AND MANAGEMENT) REGULATIONS (CDM)
UK Regulations introduced in 2015 covering any construction project. Many live event construction projects (e.g. building set, raised stages etc) are covered by the regulations. 
UK Health and Safety Executive website

CONTAINER
Refers to an standardized shipping container, used for intermodal freight transport (intermodal means across different modes of transport, from ship or rail to road).
The most common sizes are either 6m (20 feet) or 12m (40 feet) in length, and 2.6m (8 feet 6 inches) or 2.9m (9 feet 6 inches) in height.
They can be hired for very cheap weekly rates, but have high transport costs. They're invaluable for creating dry storage at events, and are also used in the film and events industry as the support skeleton for huge sets / structures.

COTTER PIN
USA: A split pin metal fastener with two legs that are bent during installation, used to fasten metal together, like with a staple or rivet.
UK: Cotter; In mechanical engineering, a pin or wedge passing through a hole to fix parts tightly together

COUNTERSINKING
(Carpentry) To enlarge the edge of a pre-drilled hole to create a bevel which enables a screw head to be recessed into the wood so it is flush with, or below, the surface of the wood. 

COUPLER
Equipment used to join two other items together.
Commonly refers to a SCAFFOLD COUPLER (also known as a SCAFFOLD CLAMP or TUBE CLAMP).
A scaffold clamp is known as a Cheeseborough in the USA, believed to be named after Chesebro-Whitman Company of New York City. 

CROSS-CUT
An installed tool that has a circular saw on a track which allows it to cut across a piece of wood. A cross-cut saw should be fitted with safety guards and an electric brake to reduce the risk of harm to users. 

CYRO
Short for Cyro Acrylite, this is an acrylic sheet product (trade name Acrylite).

DANCE FLOOR
1) A vinyl floor covering, usually kept on a plastic or cardboard tube, which is rolled out and taped to the stage floor to create a surface suitable for dance. Dance floor should be left to adjust to room temperature before being taped otherwise it will not lay flat. Many different types of floor are available, including different colours and degrees of cushioning, and the product may be known by it's manufacturer's name (e.g. Marley Floor, Harlequin Floor).
2) A wooden floor which is either naturally springy or has been constructed with rubber pads under it which absorb impact, and create a surface which performers are able to jump on without damaging knees or other joints, as the floor absorbs the impact.
German: Tanzteppich

DEAD HANG
A rigging point direct to the grid / beams above the stage, not to a flying bar.

DEAD HINGE
A hinge used as a right-angle bracket.

DEAD MAN
Also known as DEADMAN'S BUTTON (DMB). This is a handle that has to be squeezed by a technician in order for a pre-programmed automation sequence to take place. If for any reason the relevant technician is not in position, the system does not allow the sequence to run.

DECK
1) Stage/Rostrum Floor (e.g. "Fly that flat in to the deck") [known in German as bühnenboden]
2) Tape deck/Record deck.
3) A steel-framed platform with a wooden top used with replaceable scaffold legs (Trade names include Steeldeck, Metrodeck (made by Maltbury), ProDeck).

DECOR
See SET DESIGNER.

DFR (Durably Flame-Retardant)
A description of cloth which has been treated to be flame retardant, and can withstand a number of washes before needing any re-treatment. See manufacturer for full details. See also NDFR and IFR.

DOOR FLAT
Scenery item consisting of a wall containing a working (practical) door.

DOUBLE PURCHASE
Counterweighted flying system where the cradle/arbor travels half the distance of the fly bar, leaving the side wall of the stage under the fly floors clear of flying equipment. The cradle of a double purchase system needs twice as many counterweights as that of a single purchase system balancing the same weight.
The wire running between the cradle and the flying bar is the purchase line.

DOUGHNUT REVOLVE
See REVOLVE.

DRAMATIC PAUSE
A brief pause (a few beats) in an actors' delivery of a line to emphasise a moment or to heighten anticipation. 
It's important that the DSM does not shout out the next line, while the lead actor is pausing dramatically. 

DROP BOLT
Vertically-mounted metal bolt which can be used to locate and hold a wheeled platform or other set-piece in place on stage. Also known as a Cane Bolt.

DRUM AND SHAFT
The Drum and Shaft mechanism used the mechanical advantage of two sizes of winding drum to enable a single rope to operate a much heavier load, sometimes multiple loads simultaneously. Using a large Drum and Shaft mechanism, all of the painted wings of a scene, borders and backdrops can be flown out to reveal the next scene, by a single operator.
Also known as a Differential Windlass or Transformation Drum, and by the slang term Chinaman. 

DRYBRUSH
Drybrush is a painting technique in which a paint brush that is relatively dry, but still holds paint, is used. The brush is applied to a dry surface (e.g. paper or primed canvas). The resulting brush strokes have a characteristic scratchy look that lacks the smooth appearance that washes or blended paint commonly have.

DUTCHMAN
Tape or material used to cover the seams between flats or to cover hinges, prior to painting.
Masking tape works well. 
The process of taping is sometimes called DUTCHING. 

DUVETYNE
See MOLTON.

DYE
A coloured substance which chemically bonds to a substrate / material to modify the colour of that material.

ELEVATION
A working drawing usually drawn to scale, showing the side view of a set or lighting rig. See PLAN.
In the US, the term "elevation" refers to a Front elevation. A Rear elevation shows backs of scenic elements. A side view of a set is known as a "section".
See also PAINTERS' ELEVATION.

END ON
Traditional audience seating layout where the audience is looking at the stage from the same direction. This seating layout is that of a Proscenium Arch theatre.
Also known as Proscenium Staging.
The end-on stage can be split into 9 areas: upstage right, upstage centre, upstage left, centre stage right, centre stage, centre stage left, downstage right, downstage centre, downstage left.
See also THRUST, IN THE ROUND, TRAVERSE.

ENTRANCE
1) A part of the set through which actors can walk onto the stage.
2) The act of an actor walking onto the stage (e.g. The entrance of the ghost is upstage left, The bishop enters downstage right).

ESCAPE ROOM
An Escape Room is an interactive live game where your team is trapped in a room (or series of rooms) until you can solve a number of puzzles. Typical Escape Rooms have a time limit of around 60 minutes.
They may involve live actors, but often there are multimedia elements, as well as lighting & sound effects and a vast array of props which act as clues (or containers for clues).
They have a great deal in common with immersive theatrical experiences, and are wildly popular world-wide.
Escape Room page

EXIT
1) A part of the set through which actors can leave the stage.
2) The act of an actor walking off the stage (e.g. The fireman exits downstage right). 
3) A stage direction making it clear when a character should leave the scene. One of the most memorable is from Shakespeare's A Winter's Tale 'Exit, pursued by a bear'. The character being pursued is Antigonus, a lord of Sicilia, who has been ordered to abandon the baby Princess Perdita.
4) A route from the auditorium to the outside, for use during an emergency by the audience. Marked by an illuminated EXIT SIGN, which is coloured for visibility (green in the UK / Europe, red in the USA). Exit signs must remain visible to the audience at all times, and local venue licencing laws will cover whether it must be illuminated at all times, and the size of the sign etc.

EYELINE
The horizon line on a piece of painted scenery.

FAÇADE
A false frontage for a piece of stage scenery, typically depicting a building. 
Term used in the film industry for a backlot street setting which is just front walls supported by a scaffolding framework to hold them up. 

FALSE PERSPECTIVE
A scenic design technique that makes a building or set appear larger than it actually is. The scale of objects that are supposed to be further from the observer is reduced to make them appear further away, even if they're not.

FALSE PROSCENIUM
A temporary frame formed by scenic canvas or vertical flattage within the proscenium arch. Used to reduce the size of the opening when putting a small set onto a large stage.
See PROSCENIUM ARCH.

FALSE STAGE
A special stage floor laid for a production. For example to allow trucks guided by tracks cut into this false floor, to be moved by steel wires running in the shallow (2 or 3 inch) void between the false floor and the original stage floor. A false stage is also required for putting a revolve onto a stage.

FEATHER DUSTING
Also known as Schlepitchka, this is a painting technique using a stiff feather duster to apply additional coloured repetitive or randomised texture to a wall / set-piece. The feather dusters (you will need many) should be the cheaper (non-fluffy) type. 
Rosco - The Art of Schlepitchka

FEV
Short for French Enamel Varnish, a stain which is a mixture of shellac and dye, diluted in methylated spirit.

FIBREGLASS
A combination of a glass mat and a resin which can be formed into a strong shell. Used in prop-making (and lots of other industries).
Also known as GRP (Glass Reinforced Plastic). 

FIREPLACE FLAT
Scenery item consisting of a partial wall and a fireplace. Another BACKING FLAT is placed behind the fireplace to mask sightlines.

FITCH
A natural hair paint brush, used for mottling or other faux finish painting techniques.

FLAME-RETARDANT
A treatment which can make props, costumes, drapes and any other porous materials suitable for use on stage by reducing the fire risk. An item treated with a flame retardant will limit or inhibit the spread of fire by not supporting combustion.
FLAMECHECK is a commonly used treatment, suitable for a wide range of materials.
Flame Retardants at Flints (UK)

FLIPPER
Narrow flat hinged to a wider one.

FLOAT
1) The action of letting a large flat fall from vertical onto it's face so that it's cushioned by the air it displaces. Care must be taken when floating flats on dusty stages, as particles can get blown around as the flat lands.
2) See Floats.

FLOAT FLATS
A technique to get a set of flats to a horizontal position on the stage floor by removing weights and braces, ensuring the area is clear and that people are wearing safety goggles if there's danger of flying dust, then footing the flats, and pushing them over so they are cushioned by air pressure and land safely on the deck.
Known as Deixar caure in Catalan, souffler un decor in French, Op de wind in Dutch.
Flats - Types and Methods

FLOWN PIECE
A piece of scenery or masking which is suspended above the stage on the flying system. 

FLY BARS
The metal bars to which scenery and lanterns are attached for flying above the stage. 

FLY FLOOR(S)
High working platform at the side(s) of the stage from which the flying lines are handled. Often are also the site for socket panels for connecting flown lighting apparatus to dimmers, and also sometimes a lighting position. Known in the US as Fly Gallery.

FLY RAIL / FLYRAIL
Originally, this was the structure where the flying lines / ropes were tied off to hold scenery and other flown equipment in position. With the advent of counterweighted systems, this refers to the area where the flying system is operated. Also known as PIN RAIL or, in the UK, FLY FLOOR.

FLY TOWER
Extension of the stage walls up to allow scenery to be flown up until it is out of sight of the audience, and to support the GRID. Known as the "flies". The ideal fly tower should be more than twice the height of the pros. arch, and is said to have "full flying height". The load on the grid is transferred to the ground via the walls of the theatre. Known in the US as the Fly Loft, and in Europe as the Stage Tower.

FLYING HARNESS
Worn by actors who have to 'fly' as part of the action of the play (typically in Peter Pan or pantomimes). The flying harness is expertly fitted to the actor, and is fully tested and certified as safe before use by professionals. Cables attach to the harness normally at the hip, or the middle of the back, via a quick release locking snap hook mechanism. There are companies who specialise in this sort of wire work, and there's no excuse for not using the professionals at all times. See also KIRBY WIRE.
Flying by Foy website
Kirby's Flying
Aerial Effects website

FLYING IRON
Rigging hardware - a metal strip designed to screw into the lower rail of a flat or other piece of scenery with a ring attached to which flying wires can be connected using a shackle.

FOAMCORE
Also known as Foam Board.
Foamcore is a lightweight and easily cut material used for mounting of photographic prints, as backing for picture framing, for making scale models, and in painting. It consists of a board of polystyrene foam clad with an outer facing of thick paper on either side. Cuts are easy to keep straight, and pieces can be glued together to form complex shapes which are widely used by set designers for set model boxes. 
Model-Making on Theatrecrafts.com

FOOT
1) The action of bracing the bottom of a ladder while a colleague climbs it (e.g. 'Can you foot this for me please? I'll only be a couple of minutes').
2) Holding the bottom edge of a flat with your foot while a colleague raises the top of it to a vertical position (known as 'footing a flat').

FORESHORTENING
The visual effect of a 3 dimensional object appearing shorter (foreshortened) when viewed at a shallow angle.
The technique can be used in scenic painting to give an enhanced effect of dimensionality, along with other techniques such as Forced Perspective.

FOURTH WALL
The imaginary wall of a box set through which the audience see the stage. The fourth wall convention is an established convention of modern realistic theatre, where the actors carry out their actions unaware of the audience.
Where the cast addresses the audience directly, this is said to be 'Breaking the Fourth Wall'. See also ASIDE.

FRAGMENTED SET
Set design term for an otherwise naturalistic set, including furniture etc, but which has only partial walls / architectural features. The edges of the set walls may be cut off in straight or jagged lines, according to the design aesthetic / tone of the production. 

FRENCH BRACE
See BRACE.

FRENCH DRAPE
A stage curtain / drape which opens from the centre in a diagonal direction, resulting in an attractive swagged appearance. The style of movement of the curtain is known as FRENCH ACTION.

FRENCH FLAT
A scenic flat which is flown into position, usually with French braces to support it when it's in position. The braces are hinged to the flat, so can be folded closed so it can be safely flown out during a scene change. Consists of a number of flats fixed together with battens. Also known as a Frenchman.
Flats - Types and Methods

FRONT CLOTH
A cloth flown well downstage in front of which short scenes are played while big scene changes are 'silently' carried out upstage. (Common in musicals and pantomime).

FULLERS EARTH
Hydrous aluminium silicate or Calcium Bentonite Clay (aka Bentonite), used in chemistry as a filter and as a binder when mixing powder paint for use on textiles. Also used by the printing industry, and for theatre, flim and TV to age and dust-down sets and costumes.  As with any dust, avoid breathing it directly or getting it in eyes. 
Creating Mess On Stage

FULLNESS
Draperies made up with deep 'gatherings' have fullness - usually requiring not less than 50% additional fabric, measured at head and foot.

FURNITURE
Items designed to perform a specific function in a home or work environment (e.g. chair, table, cupboard, shelves, dresser, wardrobe). 

G-CLAMP
Ironmongery fitting for clamping two items into position together. See also Hook Clamp.

GALLOON
A heavily decorated woven or braided trim, often using gold or silver thread, which is scalloped along one or both edges, used to decorate the edge of a costume, drape etc. 

GATE
1) The point of focus in a profile spot where the shutters are positioned and where an iris or gobo can be inserted.
2) A single base section of a folding rostrum system.
3) See NOISE GATE.

GAUZE
Cloth with a relatively coarse weave. Used unpainted to diffuse a scene played behind it. When painted, a gauze is opaque when lit obliquely from the front and becomes transparent when the scene behind it is lit . Many different types of gauze are available;
Sharkstooth gauze is the most effective for transformations, because it is the most opaque.
Vision gauze is used for diffusing a scene and for supporting cut cloths.
HoloGauze™ is a metallised gauze optimised for front projection holographic illusions.
Also known as a Scrim, American Mesh.
Gobelin Fabric is used for tapestry making and has a less coarse weave than theatrical gauze, but will work for smaller shows. 
Voile / Net curtain material will work well and takes projection very well (as the thread is much finer than cotton gauze). 
A black curtain (known as a Blinder) is sometimes needed behind a gauze to completely block light going through. The blinder is removed invisibly just before the light is faded in upstage.
Holo-Gauze
See also Lighting With A Gauze / Scrim

GERMAN MASKING
See MASKING.

GET-IN
The process of moving set, props and other hardware into a theatre prior to the fit-up. (aka LOAD IN (US) and BUMP IN (Aus.) and PACK IN (NZ.))

GET-OFF TREADS
Sometimes shortened to GET-OFFS. A means for an actor to get off a rostrum, high level etc. out of view of the audience. Usually treads. Also known as ESCAPE STAIRS

GET-OUT
Moving an entire production out of the venue, and back into storage or into transport. Usually preceded by the strike (where the set is disassembled back into component parts.
The Get Out is also known as Load Out (USA) or Bump Out (AUS.) or Pack Out (NZ).

GLAZE
Glossy finish applied as a final coat to a painted stage floor (also available as a Matt / Flat finish).

GRAND CURTAIN
(US) The main house tabs in a venue. Normally a variation of blue or red in colour, although a more neutral grey is often better for scenes played in front of it, or for taking colours and gobos as tab warmers.

GRAND DRAPE
See GRAND CURTAIN.

GREEN BAIZE
Prior to 17th century actors dying on stage, a green baize cloth was laid down on the stage to save their costumes from needing cleaning. This was also a useful anticipation builder for the audience, especially if the cloth was laid during the interval halfway into the performance.
See also GREEN ROOM.

GRIDDED
Any flying piece raised as high as possible into the flys, i.e.to the limit of travel of the flying lines, is said to have been gridded.

GROUNDPLAN
A scaled plan (overhead) view of the theatre stage area or of a set design, to enable all technical departments to ensure that everything will fit correctly into the space available. The groundplan shows all items standing on the stage floor and any permanent items which will affect the production, and the position of any flown pieces. The set design groundplan enables the lighting designer to be clear about exact location of all items, and will have the walls of the stage drawn on it so that the stage management team and production manager can plan furniture and set moves offstage.
Typical scales are 1:24 (.5' to 1 foot) or, metrically 1:25 (1cm to .25m). Venues have a base plan showing proscenium, walls, seating etc on which individual set and lighting plans can be drawn.

GROUNDROW
1) A long piece of scenery positioned at the base of a backcloth usually to mask the very bottom of a cloth or lanterns lighting a cloth.
2) Compartmentalised floodlight battens at floor level used to light the bottom of skycloths etc, often masked by groundrow scenery. 

HANGING IRON
Ironmongery fitting fixed at the bottom of the back of a flown flat to which the suspension wire is secured.

HARDBOARD
An engineered wood product made from highly-compressed wood fibres. It's cheap and hard-wearing. Oil-tempered hardboard is more resistant to wear and tear and is more waterproof, and is used as a stage floor surface. One brand name in the US is Masonite.
Wikipedia entry

HEAD CARPENTER
The head of the carpentry team that builds the wooden portions of the set.The team are sometimes known as the 'Carps' or 'Chippies'. 

HEAD FLY
The head of the fly crew who are responsibly for lifting scenery or other objects above the stage.

HEADS ON STAGE!
A shouted warning (often just 'Heads!') for staff to be aware of activity above them. Also used when an object is being dropped from above.

HEMP
A type of rope used for flying, made from fibres found within the bark of the cannabis plant.

HEMP SET
The simplest flying system consisting of a series of hemp ropes threaded through pulleys on the grid, and tied off on the fly floor on a cleat. The usual arrangement is for three ropes to be attached to a flying piece, named by their position relative to the fly floor (short, centre and long). These names are used when levelling the flying piece, and giving it a dead. The three ropes are pulled or let in together, sometimes requiring more than one person to operate. A theatre using a hemp flying system is known as a Hemp House.

HINGE
See PIN HINGE, BACKFLAP HINGE, MARIE TEMPEST HINGE.

HOGS TROUGH
A wooden addition to the rear of a scenic flat to stiffen it, which consists of two pieces of wood screwed/glued together to form an L shape. 
Steel versions (known as Whalers) are used for steel-framed scenery. 

HOLISTIC
(with reference to Scenography) An all-inclusive approach. Scenography is a holistic approach to the study and practice of all aspects of design in performance, which means that it includes lighting, scenic design, costume design, projection design etc in a single over-arching concept.

HOLLYWOOD FLAT
A Hollywood is a double-sided timber flat with a much wider edge than normal. Hollywood flats are mainly used in the film/tv business. The thicker edge gives the flat extra stability, can be easily clamped to adjacent flats, and looks more like a real wall on camera. Also known as a TV Flat or a Studio Flat. 
Flats - Types and Methods

HOMASOTE
(US Trade Name) A type of structural fiberboard used for sound insulation and roof decking etc. 
Homasote Website

HUE
The colour of a light, costume or piece of scenery (etc.). 
The term is usually linked to Saturation, which is the amount of that colour. 

HYDRAULIC
A system of controlling machinery or moving scenery using oil or water under pressure to move a piston or 'ram'. Used in many large-scale shows to automate scene changes.

IFR (Inherently Flame-Retardant)
A description of cloth which is inherently flame-retardant and will remain so for the life of the cloth. The flame retardant qualities are a feature of the material, not a treatment applied afterwards. See manufacturer for full details. See also NDFR and DFR.

IMMERSIVE THEATRE
1) A piece of linear performance where the venue has been adapted / altered to make it part of the narrative of the story. Secret Cinema events are immersive in this sense. 
2) A piece of non-linear performance where a non-theatre venue has been completely transformed into a highly detailed world within which the audience is free to roam and see various parts of the story performed in appropriate locations. The UK company Punchdrunk created the concept of audience members wearing masks which allow them to wander around the space anonymously.
Punchdrunk Theatre

IN THE ROUND
Theatre in the Round is a form of audience seating layout where the acting area is surrounded on all sides by seating. There are often a number of entrances through the seating. Special consideration needs to be given to onstage furniture and scenery as audience sightlines can easily be blocked.
Stage managers and directors often use the idea of a clock face to describe actor positions on stage (e.g. the aisle nearest the technical point is described as the 12 O'clock position, with other aisles described as 3, 6 and 9 O'clock.)
See also ARENA, THRUST, END ON, TRAVERSE.

INSET
A small scene set inside a larger one.

ISORA*
A plastic CYCLORAMA, used because of it's light transmission properties. When lit from behind, the source of light is not visible through the plastic, making complex silhouette work possible.
When used in conjunction with a BOUNCE cloth (light directed onto the bounce is reflected onto the rear of the isora) very smooth coverage is possible.

ITALIAN MASKING
See MASKING.

JACK
1) Segmented audio connector. Mono Jacks have two connections - tip and sleeve, and are unbalanced. Stereo jacks have three connections - tip, ring and sleeve.The configuration is often abbreviated (T = Tip, R = Ring, S = Sleeve), so a strereo jack is TRS, a mono one is TS. 
B-type jacks (also known as Bantam jacks) were originally designed for use in telephone exchanges and provide a high quality (and expensive) connection in jackfields.
A-type jacks are cheaper and more common, but more fragile. A type jacks are available in 2 sizes : quarter inch and eighth inch.
2) (US) A hinged brace. In the open position, it holds up a flat or other unit of scenery. A Tip Jack is a combinaton of a jack and castors so scenery can be supported or rolled. When it is in position, it is tipped to vertical. When rolling, it leans backwards.

JONES, INIGO
Inigo Jones (July 15, 1573 - June 21, 1652) is the first significant British architect of the modern period, and the first to bring Italianate Renaissance architecture to England. He left his mark on London by single buildings, such as the Banqueting House, Whitehall, and in area design for Covent Garden square which became a model for future developments in the West End. He also made major contributions to stage design by his work as theatrical designer for several dozen masques, most by royal command and many in collaboration with Ben Jonson.
He is credited with introducing movable scenery and the proscenium arch to English theatre.

JOSEF SVOBODA
Czech scenographer (1920 - 2002)
Josef Svoboda in the Backstage Heritage Collection Archive

JULIET BALCONY
A high level platform in a theatre or on a stage set that would work for the balcony scene in Romeo and Juliet.

JUTE
A natural fibre used to make hessian cloth, sackcloth, burlap, or gunny cloth. 
Wikipedia entry

KABUKI DROP
Method for dropping a cloth from a flying bar. It consists of a bar which attaches to a standard flying bar, and is able to spin around. The bar has prongs welded to it on which the drop is hung (drop has grommetted holes in the top which hook onto the prongs). Normally these prongs are above horizontal, so the drop stays hung. On cue, the pole is rotated so that the prongs point downwards, and the drop consequently falls.

KERF
The total width of the incision in a piece of wood or metal (etc.) made by a saw blade.

KEY
A section on a lighting or other technical layout plan, which denotes what the symbols on the plan refer to. 
Although many symbols are standardised, there are variations, and to avoid confusion (or errors) when rigging and laying out equipment, a key is essential to ensure the requirements of the design are correctly interpreted. 
Lighting Paperwork

KIRBY WIRE
Wire used to fly an actor.
Named after George Kirby, who devised the first pendulum artiste flying system (in 1898). His company Kirby's Flying Ballet is still supplying flying equipment now.
See also FLYING HARNESS.
Kirby Flying - History page

LADDER
1) Climbable piece of access equipment to reach a working platform or for short light-duty work at height. See ZARGES.
2) Non-climbable structure in the shape of a ladder from which lanterns can be hung in a vertical 'stack'.

LAUAN (US)
A three layer plywood made from coarse grained tropical woods. Suitable for backing, filler or light duty bracing; not suitable for structural uses or where a smooth paintable finish is desired. Also known as Phillipine Mahogany.

LEGS
Vertical drape set as masking piece at the side of an end-on acting area. Usually set up in pairs across the stage and used in conjunction with borders to frame the audiences view.
Legs are hung from flying bars, and are usually fairly narrow in width (1.5m - 3m). 
Soft legs are cloth, hard legs are flats. 
One of many possible origins of the phrase 'Break a Leg', meaning to take an extra encore from the legs after a successful performance.
French: Pendrillon (also used for wider tabs, but not full-width stage curtains)
More information on Break A Leg

LOAD STRAP
See RATCHET STRAP.

LOADING BAY
Access into the theatre for scenery and other equipment. Also called the Get In, or the Loading Dock. 

LUMBER
(US) Lumber is a US term for wood that has been processed into useful sizes. Broadly, it is categorized as hardwood or softwood. In the UK, the term Timber is used instead. 
In the US and Canada, the standard lengths of lumber are 6,8,10,12,14,16,18,20,22 and 24 feet. 

Lumber - Wikipedia entry

MAHL-STICK
A short stick used by scenic painters to steady the hand by resting its padded end against the surface being painted.

MARIE TEMPEST HINGE
Door hinge that has been reinforced by a screw lever to keep the door from opening by itself on a raked stage. Named after the actor Dame Marie Tempest (1864 - 1942).

MASKING
Neutral material or designed scenery which defines the performance area and conceals the technical areas. (e.g. a masking flat is designed to block the audiences view of backstage).
German Masking consists of 3 sets of flats or drapes lining the edges of the performance space (ie the 2 sides at 90° to the proscenium arch, and the rear of the space masked parallel to the pros. opening.) This type of masking is sometimes known as "Up and Down Masking" as it runs up- and down-stage. This term seems to be rarely used now.
French: Pendrillonnage à l’allemande
Italian Masking consists of a set of legs and borders which are set up in a configuration similar to forced perspective. The downstage legs are furthest apart, and each set of legs moving upstage is moved onstage, with the upstage set narrowest. The exact distances involved vary according to the size of the space, and the acting area required. The same applies to the borders.
Italian: quintatura
Dance or Ballet Masking consists of evenly spaced soft masking forming wings, with side lighting booms set up behind each wing. 
Hard Masking consists of solid flats, and Soft Masking is just curtains. 

MASKING FLAT
A piece of solid scenery used to prevent audiences seeing backstage (or unwanted) areas. See also BORDER, MASKING.

MASKING TAPE
Paper sticky tape used to mark out the boundary of a surface to be painted or sprayed.
UK: Masking Tape, USA: Painters' Tape

MDF / M.D.F.
Medium Density Fibreboard. Dust masks must be used when cutting MDF, as the resins used for binding the board can be dangerous.
Not suitable to use in flat construction due to weight. 

MENDING PLATE
A metal plate used to brace across a loose/broken joint on a piece of furniture, to repair or 'mend' it. Many different sizes and shapes are available. 

MISE EN SCÉNE
Although the term literally "placing on stage" in French, the Mise en Scene refers to much more than the setting of a performance or event. The term describes all of the visual aspects of a setting - props, lighting, costume as well as set design, and how the details can contribute to the telling of the story.

MOBILE ELEVATED WORK PLATFORM (MEWP)
(often abbreviated to MEWP) A piece of access platform with a wheeled base, which can sometimes be self-propelled by the operator. The best known manufacturer is GENIE.

MODEL
A scale model provided by the set designer to help all the technical departments to co-ordinate and plan a production. Used as a reference when building, painting, dressing and lighting the set. The first stage of model-making is the WHITE CARD model which shows the form of the set, but not the detail of painting / texture / colour. When that's been approved by the director, and has been roughly budgeted, the final model is produced which should look identical to the finished set on stage. This is used as a reference by scenic artists and lighting designer etc.
The fully detailed model of the set is sometimes known as a maquette.
Italian: Bozzetto
Making White Card Models
Royal Opera House - Designing and Making A Set

MODELBOX
1) A wooden box representing the walls of a theatre space in which cardboard scale models can be placed by the set designer. See also MODEL.
2) UK-based CAD in Theatre specialist. Lighting symbols for CAD programs are available as a free download.
Modelbox website

MOLTON
Also known by the trade name DUVETYNE, Molton is a medium-weight cotton fabric which is opaque, absorbent and has a brushed finish on both sides, making it a cheap substitute for wool. Can be fire-treated, but is not inherently fire retardant. Available in many colours from theatrical / scenic suppliers.

MONKEY POLE
A stick threaded at one end with the line used to cleat two adjacent flats together, enabling the flats to be quickly and silently joined or separated. The stick remains attached to the line and flat of which it forms part.

MOUSE
Moving part of a scenic automation system. Mice are pulled along tracks by cables under the stage floor, which has a groove cut in it following the track. The mice can be made useful by inserting a metal SPADE through a wheeled piece of scenery into the mouse, which then pushes or pulls the scenery with it. The scenery sometimes has additional guide pins which move in additional guide tracks which allow the scenic piece to move in more complex directions.
In the USA, a Mouse is called a DOG, and the Spade is a KNIFE.

MUSLIN
A lightweight cotton cloth in a plain weave.

NDFR (Non-Durably Flame Retardant)
A description of cloth which has been treated to be flame retardant, but will need to be re-treated after the cloth is washed. See manufacturer for full details. See also DFR and IFR.

OISTAT
International Organisation of Theatre Scenographers, Technicians and Architects.
OISTAT website

OLEO DROP
A way of rigging a cloth / backdrop with no flying space. The cloth is attached to a flying bar at the top, and to a roller at the bottom. Operating lines around the roller allow the cloth to be rolled up as the roller is lifted up, so that it reveals whatever is behind it.
Also known as a ROLL DROP. 

OPERATING SIDE
The side of the stage (either stage right or stage left) where the fly lines are operated from.

OSB
Short for Oriented Strand Board, also known as Aspenite or Flakeboard. A type of engineered sheet timber / lumber similar to particle board, formed by adding adhesives then compressing layers of wood strands (flakes) in specific orientations (from Wikipedia).

OUT
Flying terminology, means up (out of sight).
"Tabs Out" means to to fly the curtains at the front of the stage out of sight (up into the fly tower). 
The opposite is In, which is to fly something into view (down towards the stage). 

OUTRIGGER
An extendible leg to increase the stability of access equipment (eg Tallescope, Scaffold tower).

OVERHEAD PROJECTOR (OHP)
Classroom projector commonly used before digital projection became affordable, where text or images printed or drawn/written on a horizontally-placed acetate (clear plastic) film can be projected via a lens and mirror onto a vertical wall or surface. Still used for shadow-puppetry in small-scale applications (where bright, clear images can be obtained from small puppets placed on the horizontal platform), and in scenic / prop applications where a line drawing printed onto acetate can be hugely enlarged to trace onto a large piece of scenery / cloth, hung vertically.

PAINT CHIP
(US term) A sample card showing examples of a particular range of paint colors. Known in the UK as a Swatch or Sample. 

PAINT FRAME
Large vertical wooden frame from which cloths are hung for painting. The frame is often winchable for easy access.

PAINT HOOD
Cabinet with extraction system used for spray painting small items for long periods of time. 
Paint spraying for small props should be carried out in the open air wherever possible. Use modern spray paints marked as having 'low VOC' (volatile organic content) which are less harmful when breathed in. 
Always wear a suitable face mask to avoid breathing anything harmful. 

PAINTER'S ELEVATION
A detailed working drawing of the paint job needed on every scenic piece or prop for a production. Each item is shown to scale, front-on, so the required paint job can be clearly seen. Scenic Artists use the elevation as a layout and color guide.

PARALLEL
1) The folding frame that forms the base of a readily portable platform.
2) The opposite of SERIES when referring to wiring two loads into one outlet. The two loads share the available current, but are both given the same voltage.

PASMA
UK trade association for the mobile access tower industry. The acronym stands for Prefabricated Access Suppliers’ & Manufacturers’ Association Ltd.

PELMET
A narrow strip of cloth or wood at the top of a door or window to hide the fittings. A PELMET CLIP can be used to fix a pelmet into place above a window on a piece of scenery.

PERIAKTOI
(Greek) Term for three-sided flats mounted on a rotating base. Used in rows to produce easily changed backings. Sometimes informally known as Tobelerones (or Tobes) due to the resemblance to the triangular shape of the chocolate bar.

PICKLE
Small handheld motor controller that plugs into a cable connected to a winch or other motorised system.

PILOT HOLE
A narrow hole drilled into a piece of wood (or into multiple pieces of wood that are to be screwed together)  so that when a larger screw is driven into the wood, it does not split the wood. 

PIN HINGE
Backflap Hinge with removable pin used to join two pieces of scenery together (ie one half of the hinge is on each piece of scenery).
Originally manufactured by Triple E in the UK. 
Triple E Pin Hinge at the Backstage Heritage Collection

PIPES
US term for the bars on which scenery and lanterns are flown.

PLAN
A scale drawing showing a piece of scenery, the whole set, lighting layout etc from above.
Lighting plans are usually drawn onto the theatre's GROUNDPLAN, which shows the whole stage and (at least) the front row of audience, and has the scenic design drawn onto it. The groundplan usually includes the permanent flying bars in the venue, often drawn down the side of the plan on both sides of the stage. 
A view from the side of the set (or a piece of scenery) is known as an SECTION, usually a slice through the centre line of the stag, showing the stage floor, vertical heights of scenery, lighting bar (and flown scenery) positions, and also lighting positions in the auditorium, and is used for checking lighting angles etc. 
An ELEVATION is a similar vertical slice through the venue, or individual scenic elements, and can be drawn from the front, back or side, depending on where the important detail is.
A FLOOR PLAN shows the layout of furniture / scenery for a particular show, or for an individual scene. It shows the stage area only. 
A RENDERING shows how the audience will see the set, from the auditorium, and is often in full-colour. A different rendering may be done for each scenic layout used in the show. 

PLANE
Woodworking tool used to shape wood by running a blade over it.

PLEXIGLASS
(Trade Name) Transparent acrylic plastic sheet, used to replace glass in situations (e.g. on stage) where real glass is a safety risk. 
Plexiglass is a made by cell-casting acrylic, rather than the cheaper extrusion method used for many acrylic products. 

PLUMB LINE
A slim weight (known as a plumb bob) on a thin string used to determine a vertical line on a large piece of upright scenery or suspended cloth. 

PLY
Short for Plywood.

PNEUMATIC
A system using pressurised gas to create mechanical motion. In theater, pneumatic systems are used to move heavy objects such as seating platforms or permanent scenic features on air castors. Older theaters may have pipe organs which operate pneumatically, or inflatable structures for specific productions. Pneumatic tools such as paint sprayers and nailguns are also used.

PODGER
A ratchet spanner with a long bar to use as a lever to tighten the bolt.
See also Quad Spanner

POLYSTYRENE
Also known as Beadboard (US) or Styrofoam (brand name), this lightweight synthetic material is ideal for carving rough shapes for use on stage. It should always be treated with a fire-proofing product before being used on stage, as it's highly flammable. Products such as Rosco Foamcoat add this fireproofing as well as providing a primed surface which is ready for painting.

PORTA REGIA
('Royal Door') The central entrance in the scaenae frons, the permanent architectural background to the stage of a Roman theatre. 

PORTAL
An archway made by combining wings/legs and border. Also a decorative framing, columns and pediments or filigree or other that frames the stage.
In Dutch, the portaalbrug (portal bridge) is a heavy-duty portal consisting of a horizontal bridge with a lighting bar mounted below it, along wtih two vertical legs. 

POST-MORTEM
(Latin: After Death) After a production or project has ended, a review of what went wrong (and what went well) is recommended, to learn from mistakes or successes, to ensure the next production / project goes more smoothly. This is known as a Post-Mortem (which is also the name of an examinaton of a body after death to identify the cause of death). 

POUNCE
A pounce is a craft paper stencil with small holes punched (or pounced) through it following the lines of a design or layout. The stencil can be applied to a piece of set, and a piece of chalk or charcoal or powdered paint is rubbed onto the stencil so that colour is transferred through the pin holes. Alternatively, a pounce bag (coarsely woven cloth bag containing chalk or charcoal) is repeatedly applied to the stencil so that the chalk or charcoal is transferred through the stencil to the scenic piece.
National Theatre Scenic Painting - Pouncing

PPE
(UK - Health & Safety) Abbreviation of Personal Protective Equipment. The equipment that's needed depends on the task and risk assessment but could include: steel toe-capped boots / shoes, protective headgear, gloves etc.

PRACTICAL
Any object which appears to do onstage the same job it would do in life, or any working apparatus (eg light switch or tap).
A window within the set which has to open is a practical window.
Light fittings which have to light up on the set are called Practicals, and if they're suspended from the rig, they're Hanging Practicals. 

PRODUCTION MEETING
A gathering of key production staff during the months leading up to a performance or event. The aim of the meeting is to come to an agreement about any questions raised during rehearsals or the construction phase, to deal with any budget problems, confirm detailed schedules and to keep the process moving forward successfully. Decisions should be written down and circulated to those present and anyone that couldn't make the meeting. 

PROFILE
1) A type of lantern with at least one plano-convex lens which projects the outline of any chosen shape placed in its gate, sometimes with a variable degree of hardness/softness. Profiles include four beam-shaping metal shutters, a gate to take an iris or gobo and an adjustment to make the beam smooth and even ('flat') or hot in the centre ('peaky'). See Bifocal Spot, Zoom Profile.
2) Shaped piece of scenery added to the edge of a flat instead of a straight edge. Also known as a cutout.
3) Blocking notation for an actor that is facing directly offstage. Right Profile is facing off stage right, Left Profile is facing off stage left. 
Types of Lantern
Blocking Notation

PROPERTIES
See PROPS.

PROPERTY MASTER / PROP MASTER
Member of the creative team who has responsibility for all of the PROPS used in the production (US).

PROPPING
The task, often performed by stage management in the UK, or by the scenic designer in a small company, of going around finding / borrowing / buying / making props for the production.
It's essential that a clear record is kept of the source of the props so that they can be efficiently returned at the end of the show. Reference books are used to ensure the items are correct for the time period of the production.

PROPS
(Properties) Furnishings, set dressings, and all items large and small which cannot be classified as scenery, electrics or wardrobe, and which actors interact with. Props directly handled by actors are known as HAND PROPS, props which are kept in an actors' costume are known as PERSONAL PROPS.

RAG
(Aus) Main set of tabs at the proscenium arch.

RAG ROLLING
Also known as RAGGING. A painting technique used by scenic artists to quickly get a complex textured paint effect over a large area. A base coat is applied first, which is allowed to dry, then a contrasting colour is applied, and while still wet, a scrunched up piece of rag is dabbed at the area to remove the still-wet top coat in a random pattern. Alternatively, an unevenly tied rag around a paint roller can be run over the wall to achieve the same effect.

RAIL
1) See flat.
2) Same as Flyrail. In US theatres, a RAIL CUE is the same as a FLY CUE in the UK.

RATCHET STRAP
Woven strap with a ratchet tensioner used for securing a load in a lorry. Also known as a LOADSTRAP.

RENDERING
1) (3D Design) The process of producing a real-world style image within a 3D design program. Depending on the computer power, a fully rendered image can look as good as a photograph of the real world equivalent. Rendered images are used by lighting, scenic and multimedia artists to present ideas to other members of the production team.
2) (Design) The art of creating an illustration on paper showing how a design concept will look when built. 

RETURN
1) Flats joined to the DS edge of flats of a set or unit that 'return' into the wings. They help mask and also keep the DS edge of a set from looking raw.
2) A financial report given to theatre management staff by the box office manager on a daily or weekly basis setting out the takings for performances (known as the Box Office Returns). 
3) Route for an auxiliary signal back into a sound mixer (see also SEND).

REUTLINGER
A range of adjustable steel wire fittings which can be used to suspend a static load and adjust the height easily. Available from Doughty Engineering.
Doughty Engineering website

REVEAL
A return which is at right angles to a flat, and suggests the thickness of a window, wall, doorway etc.

REVERSE AND REPEAT
A shorthand used on scenic design drawings for simplifying the drawing of complex or detailed objects. Instead of trying to accurately reproduce a hand-drawn series of details, a centre-line is drawn and the other side of the object is drawn as just an outline with 'R&R This Side' written next to it. When building the item at full scale, the details will be identical (but reversed) on  both parts. 

REVOLVE
A turntable built into the stage floor on which scenery can be set and then driven into view. Can be electrically chain driven either as part of an automation system or via simple start/stop controls, or manually rotated. A revolve can also be built on top of an existing stage.
A partial revolve with a stationary centre section is known as a DOUGHNUT REVOLVE.
In the US, a Revolve is often known as a TURNTABLE.
German: drehscheibe
See also WAGON STAGE, JACKKNIFE STAGE.

RIG
1) The construction or arrangement of lighting equipment for a particular production.(noun)
2) Installing lighting, sound equipment and scenery etc for a particular show.(verb)

RIGGING
1) General term for the systems and equipment that suspends lighting and scenic equipment above the stage or performance space. Riggers are responsible for setting up the equipment initially, and there should be rigorous (no pun intended) systems in place to test and check all flown equipment regularly.
2) The act of hanging a lantern / instrument on a lighting bar is known as Rigging a Lantern. This takes place during the Rigging Session, whilst rigging a Pipe / Bar etc. 
The process for rigging an instrument is as follows (this assumes the lighting bar is flown in to stage level):
- Check the lighting plan / rig plan for the correct arrangement and position of instruments on the lighting bar. 
- Select the next instrument as shown on the plan
- Check the instrument operates correctly (this may have happened earlier in the day)
- Hang the instrument on the bar. Tighten the clamp. 
- Point the lantern in roughly the right direction (as shown on the plan)
- Connect the safety cable around the bar.
- Plug in the power cable
- Prepare the lantern for use by inserting any required accessories (e.g. colour frame with gel or gobo in gobo holder), and opening barndoors (where fitted) or pulling out shutters. 
Lighting Rigging Positions

RISER
1) Any platform on stage. For instance, the series of platforms for choral presentations are called choral risers, the rostrum on which a drumkit and drummer is positioned is the drum riser.
2) The vertical portion of a step which gives a set of treads its height.
3) A microphone which can be raised through a small trap in the stage floor to a convenient height for an actor. Usually positioned just upstage of the footlight position, centre stage.

ROLL DROP (US)
See OLEO DROP.

ROLLER
A system whereby cloths can be rolled up/down instead of flying in/out in a theatre where there is no fly tower, or limited flying height.

ROSTRUM
(plural ROSTRA) A portable platform, usually in the form of a collapsible hinged framework (Gate) with a separate top (Lid).

RUCHE
(pronounced ROOSH) A pleating or gathering of cloth / drapes.

RUNNER
1) Climbing - abbr. for 'running belay'. An intermediate means of protection where an anchor is placed through which the climbing rope can run. In the event of a fall, the climber should fall only as far as the length of rope between him and the highest running belay he has arranged will allow. The rope absorbs the energy in the fall provided the belay and belaying is sound and the running belay holds firm.
2) A Tab Track Runner is a plastic or wooden wheeled support into which a curtain hook is clipped, which then runs along the tab track. There should be one runner for each curtain hook. Also known as a BOBBIN. See also TRAVELLER. 
Submitted by Chris Higgs

RUNNERS
1) A pair of curtains parting in the centre and moving horizontally, particularly those used in a downstage position in variety and revue productions.
2) Persons employed as production assistants to do odd jobs and errands during a production period.
3) Strips of carpet used backstage to silence actors' shoes during performance.

S.W.L.
Safe Working Load. The weight load that lifting equipment is expected (and designed) to be able to support safely.
The term has now superseded by WLL (Working Load Limit).

SAFETY EDGE
A safety sensor on the edge of a piece of automated scenery (usually a moving platform) that the automation system uses to detect something or someone out of place and take appropriate action.
See also STAGE EDGE. 

SAND BAG
A canvas bag or sack, sealed at one end and tied at the other end, used to act as a weight. A sand bag can be attached to an unused flying spot line to stop it running back through the pulleys, and to enable it to fly in without fouling adjacent equipment.

SATURATION
The amount of colour in a lighting state, paint treatment or costume design.
The term is usually linked to Hue, which is the colour of a light, costume or piece of scenery (etc.). 
A de-saturated treatment has less colour than before. 

SAW
There are a number of types of saw used in scenic construction / prop-making.
Bandsaw - A thin saw blade in a continuous loop which is driven by an electric motor and can be used to cut fine details in sheet materials. 
Circular Saw - A powered rotating saw blade held in a housing with built-in guards and guides which allows it to be moved along a large sheet of timber to cut a straight line. 
Hacksaw - A thin metal blade which is held in a metal adjustable frame, used to cut metalwork or other fine materials, by hand. 
Mitre Saw - A powered electric saw similar to a circular saw, which is mounted on an adjustable hinged arm which allows it to be lowered at a range of different angles to cut a piece of wood held in a clamp on the base of the saw. 
Scroll Saw - A smaller version of a Bandsaw which is used to cut intricate shapes in smaller pieces of wood. 
Table Saw  - A vertically rotating electrically powered saw blade fitted with a guard, which is used to cut horizontal sheet material. Care must be taken to ensure the guard is working correctly and that the material is handled properly so the hand of the user is never in danger. 

SBTD
Society of British Theatre Designers.
SBTD Website

SCAFFOLDING
1) System of pipes, clamps and boards which is used in the construction industry to form levels to improve access to high buildings either during construction or maintenance. Shortened to Scaff. 
2) The same system can be used for set construction, with adequate supervision by experienced / qualified persons. 
3) Scaff tubes / pipes are 48mm in diameter and are used as vertical legs on platform systems by various manufacturers including Steeldeck, Metrodeck, Prolyte Staging etc. Originally made of steel, scaff tubes are usually now made from aluminium which is a much lighter weight and therefore easier to work with and safer from a manual handling point of view.
4) Horizontal bars to rig lighting equipment from are made from scaffold tubes (48mm diameter). 

SCENERY
The flattage on the stage and any flown scenery or cloths that have been assembled by the set team, under the direction of the set designer for a particular performance. The arrangement of scenery for a particular scene or part of the performance is known as the 'set'.

SCENIC DOPE
A thick, often textured, finish used to add interest to flat painted surfaces or props. 
Commerical variants include Rosco Foamcoat, Sculpt or Coat etc.

Eric Hart: Scenic Dope and Monster Mud'

SCENIC PAINT
Traditionally, a mixture of glue size, water and pigment. Modern practice has also adopted PVA (emulsion glaze) as a bonding medium which can be used when scenery has got to be washed and used again.

SCENOGRAPHY
See SCENOGRAPHER.

SCISSOR LIFT
A scissor lift is a type of aerial work platform (AWP), also known as an aerial device, elevating work platform (EWP), or mobile elevating work platform (MEWP).
The AWP is a mechanical device used to provide temporary access for people or equipment to inaccessible areas, usually at height. The MEWP can usually be driven around the work area by the operator at height to provide safe access to a wide area, on a flat floor. Scissor lifts have also been used in scenic automation to provide a moveable platform, often built onto a moving base. The scissor lift is used because it is a self-contained device which requires no construction for it to operate within, and which does not extend beyond the horizontal dimensions of the platform.
The mechanism to achieve the vertical lift is the use of linked, folding supports in a criss-cross X pattern, known as a pantograph (or scissor mechanism). The upward motion is achieved by the application of pressure to the outside of the lowest set of supports, elongating the crossing pattern, and propelling the work platform vertically. The platform may also have an extending bridge section to allow closer access to the work area, because of the inherent limits of vertical-only movement.
The contraction of the scissor action can be hydraulic, pneumatic or mechanical (via a leadscrew or rack and pinion system). Depending on the power system employed on the lift, it may require no power to enter descent mode, but rather a simple release of hydraulic or pneumatic pressure. This is the main reason that these methods of powering the lifts are preferred, as it allows a fail-safe option of returning the platform to the ground by release of a manual valve.

SCREW EYE
A threaded metal ring screwed to the rear of a flat for securing a stage brace. Sometimes known as a Coach Eye. 

SCRIM
1) A coarse gauze
2) A fine metal mesh used to reduce the intensity of light from TV lanterns without affecting colour temperature.
3) Plastic gauze-like material used to line Heras fencing at festivals and other events to act as a partial sight-screen, and also to make the fencing tone in with surroundings.
See also Lighting With A Gauze / Scrim

SCUMBLING
A scenic artist technique for adding atmosphere and texture to a painted surface, by applying a thin layer of partially transparent GLAZE. The glaze layer can vary between being transparent or opaque, but best results are obtained with opaque light colours over a dark base. This can produce a cloudy effect because it allows some of the painted surface below to remain visible, but not all of it.

SECTION
See ELEVATION.

SERGE
Fabric used for masking curtains in theatres. Inherently-Flame-Retardant (IFR) Black Wool Serge is the most common. 
Wool Serge at Showtex

SET
1) To prepare the stage for action. (verb) - e.g. 'Have you set the chairs for Act 1?'
2) The complete stage setting for a scene or act. (noun) - e.g.'What's the set for the finale?' French: décors.
See also RESET. 

SET DESIGNER
Member of the artistic team for a show who works with the director to create the scenic 'look' for the stage throughout the show and any accompanying props.  They sometimes also design the costumes.
The set designer works with the production manager to ensure the design stays within the budget. Many theatres have a stock of scenery which means that items can be reused by recovering or repainting in a different production
In Europe, the set design is sometimes called 'Decor'.
See also MODEL, SCENOGRAPHER.
Scenic Design at Theatrecrafts.com

SET DRESSER
Member of production staff who is responsible for the props and furniture that are required on the set. This position only exists in larger organisations. Set dressing is often the job of the stage management department.

SETTING LINE
Imaginary line running across the width of the stage, in line with the proscenium arch, which is marked on the groundplan and is used as a reference when planning set and furniture layouts etc. Usually the furthest downstage anything can be set without fouling the house tabs.
Known in some theatres as the PLASTER LINE - this refers to the upstage edge of the proscenium wall.
See also CENTRE LINE.

SHEAVE
The wheel in a pulley block which carries the wire or rope.

SHIM
A thin piece of material used to fill a small gap between pieces of scenery, or to reduce wear between two pieces of (e.g.) staging.

SHOW CLOTH
Front cloth painted with a design specific to a particular show, sometimes containing the show logo or title.

SHOW ELEMENT
Term for an item of scenery or prop required for a production.

SKELETON SET
A piece of scenery consisting of an unclad / uncovered framework structure, made from wood or metal (often scaffolding). 

SLIP STAGE
A large wheeled stage platform which can be stored into the wing and can traverse the stage, usually mechanically driven. Common in large opera houses. Also known as a Stage Wagon.
Russian: Ñ„урка

SNAGGING
Contruction industry term for the process of looking at a completed building and making lists of problems, breakages or imperfections in the result. These 'snags' are then addressed by the building company so that there are none by the time the building is occupied by its' end users. Term could also apply to the same process of checking for problems around a set build before the actors are let loose on it. 

SNAP HOOK
A plastic or metal 'S' hook used to hang tabs etc. A sprung catch prevents the hook becoming detached.

SNAP LINE
Chalked piece of string which, when stretched tight and 'snapped' is used for marking straight lines on stage or on scenery as a painting aid.

SNOW BAG
Long narrow cloth bag fixed between two flying bars filled with artificial snow. When one of the bars is flown in and out the snow is shaken out onto the stage.

SNUB
US term. To sieze the lines on a flying piece to prevent it's movement, either with another rope or with a mechanical line locking device.

SPADE
Thick metal blade which is inserted through a piece of moving scenery into a MOUSE to allow the movement of the scenery to be controlled by an AUTOMATION system.
In the USA, a Spade is called a KNIFE (and the Mouse is a DOG). 
There are usually two spades inserted into a piece of scenery or furniture; one is the DRIVE (connected to the Mouse which is attached to the motor system) and the other is the GUIDE. 

SPADING UP / SPADED UP
The act of preparing an item of scenery to be moved by a scenic automation system using a MOUSE / SPADE system.

SPANSET
(Trade Name) Sling and safety equipment manufacturer, whose name is often generically used for a roundsling. Spanset were the originator, and popularised the modern day roundsling.
Spanset website
Additional information submitted by Chris Higgs.

SPATTERING
A scenic artist technique for breaking down a painted surface to make it look more interesting, by taking a paint brush and flicking it to throw random spatters of paint.

SPEEDRAIL
System of low-profile scaffolding clamps using allen keys to secure them in place. Used for a range of theatre / exhibition projects. Made by Hollaender in the USA.
Hollaender website

SPONGING
A scenic artist's technique to apply a textured paint finish to a piece of scenery or a prop, achieved by dipping a natural sponge into paint and then applying it to the scenery.

SPOTTER
Member of the fly crew who's responsibility is to check it's safe to fly an item on cue. Sometimes this role is taken by the flyman / fly operator him/herself. It's essential there's ALWAYS visual confirmation it's safe to move any flown object. A stage manager might not have time to check the stage is clear before giving the cue to fly so it's important someone else has the authority to NOT FLY if there's someone or something in the wrong place.

SQUINT
To capture the overall feel of a complex scene or object, rather than approaching it photographically (every detail in sharp focus), an artist will often (literally) squint, to see an approximation of the colour tone and light/shadow in the object or scene, and reproduce that, to give the essence of it, without needing to spend too much time on exact details. 
This is even more important with scenic art, where the audience might be 20-30 feet from the scenery, so any fine detail is unnecessary. 
The Art of the Squint - David Garrison

STAGE BRACE
See BRACE.

STAGE LEFT / RIGHT
Left/ Right as seen from the Actor's point of view on stage, when they are facing the auditorium. (ie Stage Left is the right side of the stage when looking from the auditorium.)
Stage Right = OP (Opposite Prompt) Abbreviated to SR. French: Cote Jardin, Netherlands: Toneel Links (translates to Stage Left!)
Stage Left = PS (Prompt Side) Abbreviated to SL. French: Cote Cour, Netherlands: Toneel Rechts (translates to Stage Right!).
NB: The Netherlands, Portugal and Germany use the opposite to the rest of Europe; i.e. Stage Left UK = Stage Right. The directions are seen from the director's and audience's perspective, NOT the actors. In Portugal Isquerda (left) is the equivalent of UK Stage Right and Direita (right) is the equivalent of UK Stage Left.

STAGE PLAN
A diagram showing the layout of the stage area from above, usually with the audience at the bottom of the plan. The plan is drawn to scale, so it can be used for determining the actual position of items on the stage, so they can be replicated in a rehearsal room, for example. 

STAGE WEIGHT
See BRACE WEIGHT.

STAGECRAFT
Stagecraft refers to any technical aspect of theatre production (and also sometimes refers to film / TV production). It includes working in technical areas such as lighting, sound, scenic construction, costume & prop construction, stage management and makeup. It usually does NOT refer to the creative / design aspects of those technical areas.

STAPLER
Essential tool for attaching cloth to wooden frames / flats. 

STEELDECK
Brand name for a system of metal framed wooden-topped platforms for building platforms, risers and stages which use scaffolding legs at any height. 
The system was invented by Philip Parsons in 1986, and his company PL Parsons Ltd launched the product onto the market.
A standard 8 foot x 4 foot deck weighs around 150lbs (68kg) and supports a distributed load of over 4000lbs (1800kg).

STIPPLE SPONGE
A sponge used by a scenic artist  to apply a random pattern of paint blobs to a piece of scenery. This technique is known as stippling.

STOCK SCENERY
Standard items of scenery used in a number of different performances. Many theatres have a stock of flattage or rostra platforms which are repainted and reconfigured for many different productions. Larger companies also have stock furniture which can either be used in rehearsal, or in productions. This is only possible if the company has enough physical space to store everything. 

SWATCH
A sample of fabric to demonstrate the material to use on a costume or set design, or a sample of lighting gel. A catalogue of all the gel colours made be a particular manufacturer is called a SWATCH BOOOK.
Rosco Supergel website

TAB TRACK
A high-quality durable metal track system to carry stage curtains (known as Tabs) or scenery. 
Manufacturers include Triple E and Halls. 
Former manufacturers included Furse. 
See also RUNNER, WIPE. 

TAB-TRACK
Track for suspending and operating horizontally moving curtains. May be hand or winch operated.

TABS
1) Originally "tableaux curtains" which drew outwards and upwards, but now generally applied to any stage curtains including a vertically flying front curtain (house tabs) and especially a pair of horizontally moving curtains which overlap at the centre and move outwards from that centre.
If the tabs are flown, the instruction TABS IN is used to fly them in to cover the stage, and TABS OUT reveals the stage to the audience. If the tabs move horizontally, the tabs OPEN (to reveal the stage) and CLOSE (to cover it). 
[In French, tabs are Rideau. The main tabs or house tabs are Rideau d'avant-scène. In Spanish, the main tabs are Bambalinón.
A narrow stage curtain used for masking is Pendrillon
In Italian, tabs are Sipario.]
2) TABS was a journal published by Strand Electric between 1937 and 1986, about stage lighting and other equipment produced by the company. The Backstage Heritage Collection archive has a complete collection of TABS journals for you to read online.
TABS archive

TALLESCOPE
(Trade Name) A retractable alloy vertical ladder on an adjustable wheeled base. The platform at the top is just large enough to hold one person. Used for rigging lanterns, focusing etc. Collapsible enough to fit through a standard doorway. Outriggers are used to stabilise the tower from falling sideways. Two people are used to move and steady the tallescope. Sometimes known as a 'TALLEY'.
Aluminium Access Products - Tallescope Manufacturer and Service
Access Equipment

TAT
1) (slang) Small (but still useful) offcuts of cloth or wood.
Black Tat is a small (but useful) piece of black cloth that could be used as masking behind a piece of set, or to cover something.
2) Short for Torpedo Attack Trainer - early simulator built by Strand Electric using a range of lighting effects
Torpedo Attack Trainer at the Backstage Heritage Collection

TEASER
1) Border, usually black, set behind the proscenium and linked with tormentors to form an inner frame to the stage, and to mask lighting bars and the upper parts of the fly tower. (Known in the USA as a VALANCE)
2) A brief advert (video or audio) which is designed to generate interest in a forthcoming performance or event. 

TEMPORARY DEMOUNTABLE STRUCTURE (TDS)
(UK Health & Safety) Any structure built for an event, whether it's staging, seating or a marquee or similar outdoor structure. 
UK Health and Safety Executive website

TENSION WIRE GRID
Abbreviated to TWG. A mesh above the stage comprised of steel wire under tension which can be safely walked on, and is transparent to light. 

THIMBLE
Protective metal or plastic loop used to reinforce and protect the eye at the end of a wire rope. Specifications vary according to use, but all conform to basic rules of proportion in forming the correct size loop for the rope diameter/type.
Submitted by Chris Higgs

THROW LINE
A rope used to hold adjacent flats together as one via cleats.

THUMBNAIL SKETCH
A series of exploratory or explanatory small sketches which help to show design concepts and how parts of them may appear when built. Often contains views from different angles, and may be highly detailed, but only show a small part of the overall design. 

TOENAILING
(Carpentry) Offsetting two nails into a wood joint so they are at opposite angles to each other, which help to make the joint rigid. 

TOGGLE
A support at the middle of a scenic flat (ie not the rails which form the top of bottom of the flat), which sits between the vertical stiles. Especially important for canvas flats, where there should be a toggle approximately every 75cm (2 feet 6 inches), to provide structural strength to the flat.

TORMENTOR TEASE*
TO BE DEFINED

TORX
Type of screw fitting, consisting of a 6-point star shape. This type of screw is increasingly being used in construction / scenic industries, as it is more hard-wearing (and more difficult to damage the head) than normal Philips / Pozi-Drive screws. 
Torx screws can also be found in some audio-visual / consumer equipment, which has no user-servicable parts inside. 
There are a wide range of sizes of Torx screw heads, denoted by 'T' then a number. Common sizes are T10, T15, T25 (although the scale runs from T1 to T100). Some manufacturers use TX numbers (rather than T) for the required screwdriver size. 
Wikipedia entry

TOURNETTE
A small horizontally-revolving turntable platform on which a piece of pottery is placed for painting.

TRACK
1) Metal structure with rails on which curtain runners are placed to enable curtains to open and close smoothly.
2) A sideways movement of a flying piece, or flown actor. See FLYING HARNESS.
3) Separate audio recording channel. Most playback / recording devices have two tracks - left and right. Some are used for MULTITRACK RECORDING and allow either four or eight tracks to be recorded onto standard media (see also DIGITAL RECORDING). Many more tracks can be recorded onto computerised systems. The most important feature of a multi-track system is the ability to record and playback at the same time (e.g. Recording vocals on track two with a pre-recorded piano on track one.)
4) An actor's (or crew member's) path through an ensemble performance, indicating which roles they take in each section of the show. Having a flexible approach to such performances means the production can be agile, and have adequate cover for actor holiday periods and any illness whilst also keeping the show fresh for the ensemble. Shows that use this approach include Hamilton and The Lord of the Rings The Musical. Swing performers are told before the show which tracks they are covering that day. Sometimes if multiple people are away, swings perform multiple tracks simultaneously - they are then said to be covering Split Tracks. 

TRAP
An opening through the stage floor.
A grave trap is a lowered rectangular section used in Hamlet etc.
A cauldron trap is a simple opening through which items can be passed into a cauldron on stage.
A star trap is a set of triangular sprung flaps in the stage floor through which an actor can be propelled from a lift below stage.
A diaphragm trap can close around an object allowing it to penetrate a previously solid wall with no visible gap around it. . 
A pivot trap is a doorway or opening with a central pivot which enables it to rotate (like a revolving door). 
The Vampire Trap was invented for James Planché's 1820 adaption of Polidori's The Vampyr. It involved two spring leaves that parted under pressure and immediately reclosed. Placed in the floor or stage wall, it could give the impression a figure was passing through solid matter.
The Corsican Trap, made for Dion Boucicault's 1852 adaption of Alexandre Dumas' The Corsican Brothers, involved an ascending track, on which a wheeled cart could be run, rising up out of the stage through a 'bristle' trap - a trapdoor covered with bristles painted to match the scenery. Once on the stage and in view, the track was covered by a sliding arrangement reminiscent of that of a roll-top desk; towhit, nothing was seen except the ghost rising up through the floor and gliding across the stage. This trap is also sometimes called a Ghost Glide. (Vampire Trap and Corsican Trap definition from 'The Cabinet of Dr Casey')
More about Traps

TRAVELATOR
A motorised horizontally-moving belt at stage level used for moving scenery or actors on / off stage. Direction and speed are easily controlled. Can be used for spectacular transformations, and are often used on Pop / Rock shows and as a way of rapidly moving furniture or actors across the stage without complicated automation. 

TRAVERSE
Form of staging where the audience is on either side of the acting area.
Also known as ALLEY or AVENUE staging. 
See also IN THE ROUND, END ON, THRUST.

TRAVERSE CLOTH
A cloth that travels horizontally across the stage on a track or rope. 

TRAVERSE CURTAIN
A curtain that travels across the stage on a curtain track. 

TREADS
General name for any stage staircase or set of steps used on stage. The step of the staircase is called the tread, and the height of the staircase depends on the number of risers. The length of the staircase is called the going. Treads can be either open or closed string - meaning whether the riser is solid or not. The carriage provides the structural support for the treads, and can be either closed carriage or open carriage. Open carriage treads have nothing above / enclosing the top surface of each riser. Closed carriage treads may have a continuous structural piece enclosing the edges of the tread unit.

TROMPE L' OEIL
French term meaning 'deceive or fool the eye'. Technique used by scenic artist to create the illusion of a three-dimensional scene or object on a two-dimensional piece of scenery.  The effect is often used in the form of FORCED PERSPECTIVE, where a set that partially exists on stage appears to extend into the distance.

TRUCK
1) Wheeled platform on which a scene or part of a scene is built to facilitate scene changing. (e.g. "This scene happens on the balcony truck"). Also known as WAGON.
2) (TV/film - verb) To move a wheeled camera sideways.
3) (Theatre - verb) To move a wheeled platform onto or off stage. (e.g. 'Let's truck the cottage scene in a the end of the second verse')

TWILL
A type of woven cloth with a pattern of diagonal ribs (in contrast with a satin or plain weave). Twill is often used for theatrical curtains because it drapes well and hides surface soiling / dirt / dust because of the complex pattern. BOLTON TWILL is a twill produced in the UK town of Bolton. It can be produced in various flame retardant types including NDFR and DFR.

UNIFIED DESIGN CONCEPT
Architectural term that refers to a document or series of drawings that shows how the various aspects of a design project are all linked thematically and/or stylistically. Theatrically, a unified design ties each scenic piece along with props, costumes and even publicity materials. Shows such as The Lion King have a very strong unified design concept.  

UNIT SET
A stage setting the structure of which remains fixed for the duration of the production. It may be added to by adding / moving furniture or using trucks / wagons to move additional scenery within it. 
A box set is a type of unit set created with flats to represent 3 sides of the environment (rear wall and side walls). 

UNITED SCENIC ARTISTS
(USA) Union for stage designers and scenic artists. Founded in 1897.
USA website

UPSTAGE
1) The part of the stage furthest from the audience. It's called Upstage because on a raked stage the stage slopes down towards the audience to improve sightlines. The furthest from the audience is literally higher due to the slope of the stage, so moving from close to the audience involves walking up the raked stage, towards 'Upstage'. 
US = Upstage, USC = Upstage Centre. USL = Upstage Left. USR = Upstage Right (see diagram)
See also DOWNSTAGE, ONSTAGE. 
2) When an actor moves upstage of another and causes the victim to turn away from the audience s/he is 'upstaging'. Also, an actor drawing attention to themselves away from the main action (by moving around, or over-reacting to onstage events) is upstaging.

USITT
United States Institute of Theatre Technology.
Founded in 1960. Publisher of Theatre Design and Technology and Sightlines journals, which are available online (see Publications in the Theatrecrafts.com Archive section).
USITT Website

VERISIMILITUDE
The appearance of reality. In scenic or costume design, the level of detail required depends entirely on the distance of the audience from the set / performers. An impressionistic approach can be used where the audience are a long distance away, with no loss of verisimilitude.

WAGON
(also known as TRUCK). A large wheeled platform which can be moved around the stage either manually by crew or by a scenic automation system. See also WAGON STAGE.

WEST COAST
(US) In theatres with reduced flying height, West Coasting is the act of bundling up a cloth or backdrop and tying it to a flying bar during a scene change so that it can be flown out of sight. Believed to originate on the west coast of the US, where rapid expansion of variety theatres with low fly towers meant this technique was universal.

WET BLENDING
A painting technique for combining two colours into a subtle blend, used to create shadow or shading effects. The first colour is applied, then immediately the second colour is applied on top, before the first has dried. The brush is then used to blend the colours together as desired.

WHALER
A low-profile steel stiffener for steel-framed scenic flats.
See also Hogs Trough. 

WILD WALL
(Film-making) A piece of scenery (e.g. a wall in a room) which can be removed to allow performers or equipment to pass through it, either during scene changes or as part of a sequence. In film production, sets have to be flexible to allow crew members and large cameras to film in areas formerly occupied by scenery, especially if it's a small room set. 
Some theatrical productions use the same techniques to enable illusions or sudden appearances / disappearances, or to enable crew to do scene changes in seemingly closed locations. 

WING AND DROP SET
A set consisting of painted backdrop and accompanying painted wing curtains. When the location changes, both the backdrop and set of wings are flown out and replaced with another set. This is common in opera, ballet and (UK) pantomime performances.

WING FLATS
Flats which mask the entrances at the sides of the stage (wings).

WORKING DRAWINGS
Plans from which carpenters and other technicians can build the scenery.

WYSIWYG
Acronym of 'What You See Is What You Get'. Mainly used in the context of a software tool for lighting design and production administration. Capable of stunning 3D rendering of lighting states, and direct connection to a lighting control desk. Enables accurate pre-visualisation of lighting designs and greatly increases the understanding between director / producer and lighting / scenic designer in the early stages of a production.
WYSIWYG product details

ZARGES
(Manufacturer) German manufacturer of a range of ladders. Commonly refers to the 3-part ladder used on many stages around Europe.
Zarges website
Access Equipment

ZINGER
Term used in artistic rendering (illustration) of a theatre set or prop. The zinger is to the brightest part of a highlight, which gives the illusion of a 3d object accurately lit.