At a glance
| Word | What it can mean | Write instead |
|---|---|---|
| Contract grade | A use, a fabric weight, or a marketing label. No standard defines it. | The standard, the test and the result you require. |
| Crib 5 | Trade shorthand for ignition source 5 in BS 5852, one part of BS 7176 Medium Hazard. | BS 7176 [Medium] hazard, composite tested, certificate on file. |
| Fire-retardant fabric | Inherently flame-retardant yarn, or a treated cloth that needs a water soak. | Which, with the certificate and the composite. |
| Border | The front band under the seat, a band round the back, or a printed border. | Front border or seat front, on the drawing. |
| Welt, piping | A cord in a seam. Two words, and workrooms use them differently. | Welt, [ ] mm cord, self-fabric. |
| Rake, pitch, recline | An angle from the vertical, the horizontal or between seat and back. | The angle and the datum, on the drawing. |
| Drop | The seat-to-table gap, or another distance. | Seat-to-top gap, [ ] mm. |
| Scatter back | Loose cushions against a low back, not a back with a few cushions added. | Back style, cushion count, fill and size. |
The eight words that most often cause trouble in a brief.
The parts of a sofa
Upholstery vocabulary is mostly trade usage. A workroom, a designer and a client can each mean something slightly different by ‘tight back’, ‘border’ or ‘welt’, and a quote built on the wrong meaning is expensive to correct. A few terms do have exact meanings, because they come from fire guidance or standards. This glossary keeps the two apart: every entry is marked with its source, or as trade usage.
The drawing names thirteen parts of a loose-back sofa, in front view and in section. The numbers are used in the tables below. The first nine are parts of the sofa, 10 is the outer back, 11 and 12 are the two angles (the dashed lines are the horizontal and the vertical they are measured from) and 13 is the finished seat height.
Seating shapes, constructions and measurements
Source keys. FIRA-CG: the FIRA and British Furniture Confederation guide to fire safety in the contract and non-domestic sectors (2011 edition on FIRA's site). FIRA-L: FIRA's page on leather types (2022). ADM: Approved Document M volume 2. BSI: a BSI Knowledge listing. Sheet: another sheet in this library, which lists its own sources. Trade: trade usage, with no standard or neutral reference found; the partner upholsterer should confirm how they use the word.
| Term | What it means | In a specification | Source |
|---|---|---|---|
| Tight back | A back where the cover is fixed over the padding on the frame, so no cushion lifts out. Smooth and tailored; it cannot be plumped or turned. | Draw it on the elevation and say whether it is buttoned or channelled. A tight back cannot be swapped later without the workshop. | Trade |
| Loose back (cushion back) | Separate removable cushions resting against a fixed back. Softer and can be turned or plumped. | The fixed back behind the cushions shows when they are moved: say it is covered. Give the cushion count and the filling of each. | Trade |
| Scatter back | Loose cushions leaning against a low back, not fixed to the frame, so they move about the seat. Casual, and needs tidying. | Give the size, filling and count. Ask the fire consultant whether loose cushions are inside the fire evidence for the item. | Trade |
| Tight seat and drop-in seat | Tight seat: the cover is fixed over padding on the seat deck and no cushion lifts. Drop-in seat: a padded panel that sits in the rails of a chair frame and lifts out, for re-covering. | Usual on dining chairs and banquettes. Say which, and whether the client expects to re-cover it: see the banquette sheet. | Sheet: banquette dimensions |
| Box cushion and knife-edge cushion | Box: a loose cushion with a flat top, a flat bottom and a side strip, giving a square edge, often welted. Knife-edge: the top and bottom panels meet at one seam round the edge, so the edge tapers. | Say which, give the boxing depth in mm, and where a seam shows. Some suppliers use other names. | Trade |
| Welt (piping, cord) | A cord sewn into a seam to define an edge. Some people use ‘piping’ for the sewing term and ‘welt’ for furnishing; others swap them. | Give the cord diameter and whether it is self-fabric or contrast, and confirm the word with the workroom. | Trade |
| Crown | The slight rise at the middle of a cushion so that it looks full and rounded when new. It settles with use. | Give the crown as a height in mm on the approved sample. Not the same as seat rake. | Trade |
| Deck | The platform under a seat cushion, often plywood or webbing, covered in plain cloth. | Say what the deck is made of, because it carries the suspension: see the sheet below on foam deck. | Trade |
| Arm style (track, roll, scroll) | Track: straight and square. Roll: the top is rolled over into a round. Scroll: the top curls outward into a scroll. | Draw the arm profile with its height. The names are not exact and workrooms add their own. | Trade |
| Front border | The covered panel across the front, below the seat cushion. ‘Border’ is also used for other bands on upholstery. | Write ‘front border’ or ‘seat front’ on the drawing, never ‘border’ alone. | Trade |
| Skirt (valance) | A band of cloth hanging from the seat base towards the floor, hiding or framing the legs. | Give the drop, the finish of the hem and whether it is pleated. | Trade |
| Banquette | A long upholstered seat fixed to a wall or built in, with tables set in front of it. | Its heights and gaps are on the banquette sheet. | Sheet: banquette dimensions |
| Seat rake (seat slope) | How far the seat surface tilts back from the horizontal, front higher than rear. (Fig. 1, no. 11) | State the angle and the datum. Confusable with back rake. | Sheet: seat slope and back rake |
| Back rake (back pitch, recline) | How far the front face of the back leans from the vertical. Some sources measure from the horizontal or between seat and back. (Fig. 1, no. 12) | The drawing must say which angle is meant: the numbers differ by 90 degrees or more. | Sheet: seat slope and back rake |
| Finished seat height | The height from finished floor level to the top of the upholstered seat. Loaded (sat on) and unloaded differ. (Fig. 1, no. 13) | Say which, and from which floor level. | Sheet: seat height, depth and width |
| Knee recess | The space under a counter for a seated person's knees. Approved Document M asks for one ‘not less than 700mm, above floor level’ at the lowered reception section, and for 1200 x 1800 mm in front if the recess is at least 500 mm deep. | We read the 700 as a clear height. Take any accessibility figure from the Approved Document and your consultant. | ADM 3.6(d), (e) |
The three drawings show the back styles, the seat styles and the arm styles. They are schematic and show the idea, not any maker's design.
Frame, suspension and fillings
| Term | What it means | In a specification | Source |
|---|---|---|---|
| Eight-way hand-tied springs | A suspension where coil springs are tied to each other and to the frame by hand. Deep, slow give; labour-intensive. The ‘eight-way’ name is not defined by any standard. | Name the system and ask the partner to describe its tying and fixings. | Sheet: seat suspension compared |
| Sinuous spring and pocket spring | Sinuous: S-shaped steel wire running front to back across the seat frame, clipped at intervals; firm and slim. Pocket: a coil sewn into its own fabric pocket so each moves independently. | Name the system and confirm the wire gauge or spring count with the partner. | Sheet: seat suspension compared |
| Webbing and foam deck | Webbing: straps woven across the seat rails. Foam deck: a rigid base, often plywood, with foam on top and no springs. | Say which: the choice sets how the seat feels and how long it lasts. | Sheet: seat suspension compared |
| CMHR foam | Combustion-modified high-resilience polyurethane foam: HR foam made to resist ignition. Domestic furniture can use it too, so the name alone is not a contract fire route. | Ask for the foam's density, hardness and ignition certificate, and say the fire route separately. | Sheet: upholstery foam and feather |
| Foam density and hardness | Density is mass per cubic metre; hardness is the force to indent the foam by a set amount. They are independent: a dense foam can be soft. | Write both, each with a tolerance, and the test method. A grade number is not the measured density. | Sheet: upholstery foam and feather |
| Fibre wrap | A layer of polyester wadding round a foam core to soften the edge and make the cushion look fuller. | The wrap is part of the fire composite and must be in the sample. | Sheet: seat cushion constructions |
| Down-proof ticking | A tightly woven inner case holding feather or down, so that quills do not poke through the cover. | Name the ticking when the cushion has a feather fill. | Sheet: feather and down |
| Feather-to-down ratio | The proportion of feather to down in a fill. More down is softer and lighter and costs more. | State the ratio and the labelling standard in the brief. | Sheet: feather and down |
| Interliner | An extra layer of fire-retardant material between the exterior cover and the filling. | It changes how the cover sits, so it must be in the approved sample and in the certificate. | FIRA-CG 2.0 |
| Upholstery composite | The combination of cover and filling materials, made up of layers such as fabric, interliner and filling. | A fire certificate applies to that combination. Seat, back and arm with different fillings are different composites. | FIRA-CG 2.0, A1.1 |
For how the fire words fit together, see BS 7176 hazard categories and how to read an upholstery fire test report.
Cloth, leather and ordering
| Term | What it means | In a specification | Source |
|---|---|---|---|
| COM and COL | Customer's own material and customer's own leather: cloth or hides chosen and bought by the designer or client and delivered to the workshop, which upholsters them. | State the metres or hides per piece, the delivery date, the batch and the test certificates needed. | Sheet: COM and COL yardage |
| Pattern repeat and half-drop | The distance after which a pattern repeats. In a half-drop, every other column is stepped down by half a repeat, so more cloth is needed to match. | Give the repeat and the match, and increase the yardage. | Sheet: COM and COL yardage |
| Railroading and pile direction | Railroading turns the cloth through 90 degrees so that the roll width runs along the length of the piece. Pile direction is the way the surface fibres of a velvet lie. | Say whether the cloth may be railroaded and which way the pile runs on every piece. | Sheet: COM and COL yardage |
| Martindale rub and cycle | A laboratory abrasion test for cloth. ISO 12947-1:1998 defines a rub as one revolution of the two outer drives and a cycle as the full Lissajous figure of 16 rubs. | Ask for the unit, the load, the standard and the end-point, not one number on a card. | Sheet: fabric performance tests |
| Pilling | Small balls of loose fibre that form on a cloth with use. It is tested apart from abrasion. | Ask for the grade and the number of rubs. | Sheet: fabric performance tests |
| Light fastness | How well dyed cloth resists fading. On the blue wool scale, references run 1 to 8 and each is about twice as fast as the one below. | Ask for the grade per colourway and the scale used. | Sheet: fabric performance tests |
| Seam slippage | Yarns sliding in a woven cloth when pulled at a seam. A property of the cloth, not the strength of the stitching. | Ask for the result for the cloth, warp and weft. | Sheet: fabric performance tests |
| Cleaning code (W, S, WS, X) | Letters on the cloth: W water-based cleaner, S solvent, WS either, X vacuum or brush only. A trade convention, not a test result. | Get the supplier's written cleaning instructions for the colourway. | Sheet: fabric performance tests |
| Aniline and semi-aniline leather | Aniline is dyed through with no surface coating: soft and natural, it takes up light and liquids easily. Semi-aniline has a thin protective coat, so it is more even and durable but still vulnerable to spills. | Seldom right for a busy venue; ask for the test report. | FIRA-L |
| Pigmented leather | Buffed, then given a coloured polymer coating and an embossed grain. The most durable and widely used upholstery leather. | The usual choice for heavy use; ask for the test report. | FIRA-L |
| Finished split and Bycast | Finished split is leather from the under layer of a hide with a polymer coating that mimics grain, weaker than grain leather and recommended by FIRA only for low-stress uses. Bycast is a split with a coloured polyurethane film bonded on; FIRA recommends testing it before upholstery use. | Avoid both where the seat is used all day, and ask for the test report. | FIRA-L |
| Nubuck and suede | Nubuck is aniline leather with the grain lightly sanded to a velvet feel. Suede is the flesh side, and the two are often confused. Both absorb liquids and mark easily. | Name the one you mean. | FIRA-L |
Fire, tests and certificates
| Term | What it means | In a specification | Source |
|---|---|---|---|
| Non-domestic (contract) furniture | Furniture destined for offices, hotels, residential care homes and similar use, which falls within the Regulatory Reform (Fire Safety) Order 2005. | ‘Contract’ is a use, not a quality grade. Say which standard and result you require. | FIRA-CG 2.0 |
| Responsible Person | Someone who owns the premises or business, or has control over them. Fire safety is their responsibility, not the designer's or the supplier's. | Ask the Responsible Person for the hazard category; do not choose it yourself. | FIRA-CG 2.0; Sheet: BS 7176 |
| Hazard category (Low, Medium, High, Very High) | The level of ignition resistance BS 7176 asks for, set against the premises. The guide's examples put offices in Low, and hotel bedrooms, restaurants and bars in Medium, but the risk assessment may assign higher or lower. | Write the category the Responsible Person sets, not ‘contract grade’. | FIRA-CG Tables 2, 5 |
| BS 7176 | The British Standard for the resistance to ignition of upholstered furniture for non-domestic seating, by testing composites. Catalogue listings show the 2007+A1:2011 edition as current. | Name the edition and the category, and ask for composite test reports. | Sheet: BS 7176 hazard categories |
| Ignition source 5 and 7 (‘Crib 5’, ‘Crib 7’) | Flame sources in BS 5852 (BSI lists the 2006 edition as current). FIRA's guide calls source 5 a wood crib. Medium Hazard adds source 5; High uses source 7. ‘Crib 5’ is trade shorthand. | Write the hazard category, not ‘Crib 5’. Passing 5 does not mean passing 7. | FIRA-CG Table 5; BSI |
| Water soak | A thirty minute soak before conditioning and testing, required for treatments (including back-coating) applied to a cover. Not required if the cover is inherently flame-retardant and has no added treatment. If unknown, soak. | Ask whether the cover is treated or inherently flame-retardant. | FIRA-CG A1.2 |
| Inherently flame-retardant and back-coated | A cloth made from flame-retarded yarn needs no further treatment. A back-coated cloth has a flame-retardant treatment on its back, so the soak applies. | State which, and attach the certificate. | FIRA-CG A1.2; Trade |
| BS EN 16139, Level 1 and Level 2 | The standard for the strength, durability and safety of non-domestic seating. BSI lists the 2025 edition as current (it replaces the 2013 edition). It covers no flammability. Level 2 is the more severe level. | Say the level for the use, and ask for the report: see the sheet. | Sheet: BS EN 16139 levels |
| FIRA Gold | A product certification scheme run by FIRA, with audits and re-testing, covering named products. | A certificate covers the products it lists, not a whole brand. | Sheet: FIRA Gold and test reports |
| UKAS accreditation | UKAS is the national body that accredits test laboratories to the international laboratory standard. It applies to the laboratory and its listed tests, not the product. | Ask whether the test is within the laboratory's scope. | FIRA-CG 2.0; Sheet: FIRA Gold |
One correction to a common version of this glossary. ‘Crib 5’ is not the line between contract and domestic furniture. Source 5 appears in the domestic regulations' foam and interliner tests as well, and for non-domestic premises the level comes from the Responsible Person's fire risk assessment: see domestic or contract fire regulations.
Writing the words into a brief
- Draw it, then name it. A one-line description of a back or arm is weaker than an elevation with the part named. Use the same word on the drawing, the schedule and the quote.
- Ask the workroom to repeat it back. For any word on the first table, ask the partner upholsterer to say in writing what they will make. Regional and workroom usage differs.
- Prefer a number to an adjective. Crown in mm, welt cord in mm, seat height in mm with its datum, angle in degrees with its datum.
- Keep the fire words exact. Name the hazard category, the standard edition and the composite. The Responsible Person sets the category.
- Make it a clause. Where a term has more than one common meaning (welt, border, tight back, scatter back, crown, rake), write that the workshop is to confirm its understanding in writing against the shop drawing before production.
- Sign a sample. One approved sample settles most disagreements about welt, crown, border and fill: see sample hierarchy and approval.
Specification wording
Paste into your schedule or specification and replace anything in [square brackets] with your own figures. Wording is a starting point: your specification governs.
Seating form
Sofa [model]: [loose back] with [2] back cushions on a covered fixed back; [tight seat / box seat cushions, [ ] mm welt]; [track / roll] arms; front border and [skirt, [ ] mm drop], to approved elevation [ref]. Crown [ ] mm on the approved sample. Finished seat height [ ] mm [loaded] from finished floor level. Seat rake and back rake [ ] and [ ] degrees, measured as on the drawing.
Cover and fire evidence
Cover [COM / supplier cloth: name, colourway, batch], [ ] metres per piece, [repeat [ ] mm, half-drop; railroaded yes / no; pile direction [ ]]. Each upholstery composite (cover, interliner, filling) to meet BS 7176 [hazard category set by the Responsible Person], with a test report naming the composite. Cover [inherently flame-retardant / treated and water soaked].
Terms used on this page
- Trade usage
- A word used in the trade with no standard behind it. Two workrooms can mean different things, so draw it and name it on the schedule.
Standards and sources
- FIRA / BFC fire safety guide (2011 edition on FIRA's site) and FIRA leather types page (2022): read 6 Nov 2026: definitions, Tables 1, 2 and 5, Appendix 1, leather types. The guide pre-dates current editions of some standards.
- BS 7176:2007+A1:2011; BS 5852:2006; BS EN 16139:2025: BS 5852 current (BSI listing read); the other two current per search results. Texts not read; confirm editions.
- Approved Document M, Volume 2 (2015 with 2020 and 2024 amendments), England: knee recess; read 6 Nov 2026.
Questions we are asked
What does COM mean in furniture?
Customer's own material: cloth chosen and bought by the designer or client and sent to the workshop, which upholsters it. The quote covers labour and filling only, so it needs the metres per piece, the delivery date, the batch and the test certificates. COL is the same for leather.
What is the difference between a tight back and a loose back?
A tight back has the cover fixed over the padding on the frame, so no cushion lifts out. A loose back has separate removable cushions against a fixed back. Both are trade terms, so draw the back and say which you mean.
What does crown mean on a cushion?
The slight rise at the middle of a seat or back cushion, so that it looks full and rounded when new. It settles with use. Give the crown as a height in millimetres on the approved sample. It is not seat rake, which is the tilt of the whole seat.
What is an upholstery composite?
The combination of cover and filling materials, in layers such as fabric, interliner and filling (FIRA's guide). Fire tests are run on the composite, so a certificate applies only to that combination. A seat, back and arm with different fillings are different composites.
Is 'Crib 5' the same as BS 7176?
No. Source 5 is a flame source in BS 5852, which FIRA's guide describes as a wood crib, and BS 7176 Medium Hazard asks for resistance to it on the composite. ‘Crib 5’ is trade shorthand. Write the hazard category the Responsible Person sets.
Does 'contract grade' mean anything?
On its own, no. FIRA's guide defines non-domestic furniture by where it is used, such as offices and hotels. It is not a quality grade or a test result. Name the standard and the result you need.
Are upholstery terms standardised?
Mostly not. The fire and test terms come from guidance and standards, but words such as tight back, scatter back, welt and border are trade usage and differ between workrooms. Ask the partner upholsterer to confirm each against the drawing.
Download the factsheet
A two-page A4 PDF with the labelled sofa drawing, the eight trouble words, 14 of the most useful definitions and specification wording, to keep with your project file.