How to Write a Fabric Specification: A Contract Guide

A fabric specification is the document that tells everyone downstream, upholsterer, contractor, client, fire officer, exactly what fabric is being used and what it must achieve. A vague specification is where contract projects go wrong. This guide sets out what a complete fabric specification contains and what certificates to require. For where each decision falls in the project timeline, see our RIBA Plan of Work fabric guide.

What a Complete Specification Contains

A specification that prevents disputes states every performance requirement explicitly rather than assuming it. The core fields are the fabric name and range, the fibre composition, the abrasion requirement as a Martindale figure, the fire standard in full (for example BS 7176 Medium Hazard, not just Crib 5), the cleaning code required for the environment, the light fastness grade, and the colourway with a dye-lot reservation instruction for larger orders. For patterned fabric, add the pattern type and repeat. For each requirement, state the standard and the figure, not a general word like durable or fire-safe.

State the Standard in Full

The most common specification weakness is naming a standard loosely. Crib 5 alone is weaker than BS 5852 Ignition Source 5 (Crib 5). Fire-rated is meaningless without the standard. A Martindale requirement should give the figure, 100,000 rubs, not high abrasion. The fuller the reference, the less room for a substitution or a dispute later. State the standard, the part, and the figure for every performance field.

What Certificates to Require

For any contract project, require the independent test certificate before the fabric is installed, not a supplier’s claim of compliance. For fire, that means the certificate from a UKAS-accredited laboratory naming the fabric, the filling used in the test, the standard, and the result. A verbal assurance or a product description is not a certificate. For a composite standard such as BS 7176, confirm the certificate names the specific foam, because the certificate is valid only for the fabric and filling combination tested. For marine work, require the IMO certificate for the relevant part. For how FR certification works and who can issue it, see our how FR treatment works guide.

Confirm the Composite and the Cleaning Regime

Two checks prevent most late-stage failures. First, confirm the foam or filling matches the fire certificate, since substituting a different foam invalidates it. Second, confirm the fabric’s cleaning code suits the environment’s actual cleaning regime, an S-coded fabric fails in a setting that uses water-based cleaning. Present the environment’s cleaning products to the supplier and get written confirmation of compatibility. For the cleaning implications in demanding settings, see our healthcare fabric guide and hotel fabric specification guide.

Request Cuttings Before Committing

A cutting confirms colour, handle, and quality before the fabric is committed to a scheme, and provides the reference sample for matching later deliveries against. Request cuttings early, and for a phased order retain the first-delivery sample to check subsequent dye lots. For cuttings, dye lots, and lead-time planning, see our lead times and colour matching guide. For the full specification library organised by environment, application, and performance need, see our fabric buying guide by purpose.

Quick answers

What should a fabric specification include?
A complete fabric specification states the fabric name and range, the fibre composition, the Martindale abrasion figure, the fire standard in full (for example BS 7176 Medium Hazard), the cleaning code, the light fastness grade, and the colourway with a dye-lot reservation instruction for larger orders. For patterned fabric it adds the pattern type and repeat. Every performance requirement should give the standard and the figure, not a general word such as durable or fire-safe.

What certificates should I require before installing a contract fabric?
Require the independent test certificate before installation, not a supplier’s claim of compliance. For fire, that is the certificate from a UKAS-accredited laboratory naming the fabric, the filling used in the test, the standard, and the result. For a composite standard such as BS 7176, confirm the certificate names the specific foam, because it is valid only for the fabric and filling combination tested. For marine work, require the IMO certificate for the relevant part.

Why does the foam matter for a fire certificate?
Contract fire standards such as BS 5852 Crib 5 and BS 7176 test the fabric and filling together as a composite, not the fabric alone. A certificate is valid only for the specific fabric and foam combination tested. If the project uses a different foam from the one named in the certificate, the certificate does not cover the installation, and new testing is required. Always confirm the foam matches the certificate before ordering.

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Buying Guide by Purpose Crib 5 Fire Guide Martindale Rub Test BS 5867 Curtains Marine Fabric

14 August 202614 August 2026

Fabric Specification Glossary for Interior Designers

This glossary defines the fabric specification terms interior designers and architects meet most often, grouped by subject. Each entry links to the full guide where the term is covered in depth. For the complete specification library, see our fabric buying guide by purpose.

Durability and Abrasion

Martindale. The UK and European abrasion test, expressed as a rub count. The higher the count, the more abrasion the fabric withstands. Contract grade begins at 40,000 rubs. See our Martindale rub test guide.

Wyzenbeek. The US abrasion test, expressed in double rubs. Not comparable to Martindale and not interchangeable with it on a UK specification. See our Wyzenbeek vs Martindale guide.

Pilling. The formation of small fibre balls on a fabric surface through rubbing. Graded by ISO 12945-2. Distinct from abrasion failure. See our pilling resistance guide.

Fire and FR

BS 5852 Crib 5. The UK fire standard for contract upholstery, testing the fabric and filling as a composite against a wooden crib ignition source. See our Crib 5 guide.

BS 7176. The specification standard for non-domestic seating that references Crib 5 and adds hazard categories and a water-soak stage. Medium Hazard is standard for hotels.

BS 5867. The fire standard for contract curtains, separate from and not interchangeable with the upholstery standards. See our contract curtain guide.

Inherent vs topical FR. Inherent fire resistance is a property of the fibre and is permanent. Topical treatment is applied after weaving and can degrade with cleaning. See our how FR treatment works guide.

IMO FTP Code. The marine fire framework for commercial vessels. Part 8 covers upholstery, Part 7 curtains, Part 9 bedding. Crib 5 does not substitute for it. See our marine fabric specification guide.

Colour and Light

Light fastness. A fabric’s resistance to fading under light, graded 1 to 8 on the Blue Wool Scale (ISO 105-B02). Grade 6 or above is needed for sun-exposed positions. See our light fastness guide.

Crocking. Colour transfer from a fabric surface through rubbing, tested by ISO 105-X12. See our colour fastness and crocking guide.

Dye lot. A record of a specific dyeing batch. Colour varies between dye lots, so a large or phased order should be secured from one lot. See our lead times and colour matching guide.

Metamerism. When two colours match under one light source but differ under another. See our colour naming and specification guide.

Cleaning Codes

W. Water-based cleaning is suitable. S. Solvent-based dry cleaning only; water can damage the fabric. WS. Either water or solvent cleaning is suitable. X. Vacuum or brush only; no wet or solvent cleaning. See our fabric care symbols and cleaning codes guide.

Construction and Materials

Velvet. A construction, not a fibre: a pile fabric that can be woven from mohair, cotton, silk, linen, or synthetic. Fibre determines performance. See our velvet types guide.

Faux leather. A coated fabric imitating leather, in three types: PVC, PU, and silicone. See our faux leather types guide.

Pattern repeat. The distance before a pattern returns to the same position, horizontal and vertical. Drives fabric wastage in cutting. See our pattern matching guide.

Cold crack. The temperature at which a coated fabric stiffens and cracks. Relevant to exterior and marine use. See our cold crack testing guide.

Quick answers

What does the Martindale rub count mean?
The Martindale rub count is the number of abrasion cycles a fabric withstands in the UK and European abrasion test before showing wear. The higher the number, the more durable the fabric. Contract-grade upholstery begins at 40,000 rubs, and heavy contract use calls for 100,000 or above. It is not comparable to the US Wyzenbeek double-rub figure.

What do the fabric cleaning codes W, S, WS, and X mean?
W means water-based cleaning is suitable. S means solvent-based dry cleaning only, and water can damage the fabric. WS means either water or solvent cleaning is suitable. X means vacuum or brush only, with no wet or solvent cleaning. The code is set for each fabric and should be matched to the cleaning regime of the environment before specifying.

Is velvet a type of fibre?
No. Velvet is a construction, a pile fabric, not a fibre. It can be woven from mohair, cotton, silk, linen, cashmere, or synthetic fibres, and the fibre determines the durability, fire rating, cleaning, and cost. Choosing velvet on appearance alone, without regard to fibre, is a common specification error.

To request cuttings, visit KOTHEA.com/cuttings.

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Mohair Velvet Faux Leather Cashmere Throws Silks Linen Textured Upholstery

Specification Guides

Buying Guide by Purpose Crib 5 Fire Guide Martindale Rub Test BS 5867 Curtains Marine Fabric

14 August 202614 August 2026

How Much Fabric to Upholster Furniture: Estimates by Type

Estimating how much fabric a piece of furniture needs is one of the most common calculations in a specification, and one of the easiest to get wrong. This guide gives working estimates by furniture type in metres, explains the variables that change them, and shows how to add the pattern-repeat allowance. For pattern matching and repeat calculation, see our pattern matching guide.

Estimates by Furniture Type

These are working estimates for plain fabric on a standard piece, based on a 140 cm wide fabric. They are starting points for budgeting and initial ordering, not a substitute for the upholsterer’s measured calculation on the specific frame.

Piece	Plain fabric estimate (140 cm wide)
Dining chair, seat only	0.5 to 0.75 m
Dining chair, seat and back	1.5 to 2 m
Occasional or accent chair	2.5 to 4 m
Armchair	5 to 7 m
Wing chair	6 to 8 m
Two-seat sofa	10 to 14 m
Three-seat sofa	14 to 18 m
Large or corner sofa	18 to 25 m
Headboard, single	2 to 3 m
Headboard, king	3 to 4.5 m
Ottoman or footstool	1.5 to 3 m

What Changes the Estimate

Several variables move the figure up from the base estimate, sometimes substantially. Fabric width is the first: the estimates above assume 140 cm. A narrower fabric, such as 130 cm, needs proportionally more length, and a very narrow fabric changes the cutting plan entirely. Pattern repeat is the second and largest: a patterned fabric needs extra length to align the repeat across panels, added on top of the plain estimate. A directional fabric or one with a pile that must run the same way on every panel, such as velvet, restricts how pieces can be cut and raises the quantity. Deep buttoning, pleating, valances, and contrast piping all add fabric. Loose covers need more than tight upholstery because of tuck-ins and hems.

Adding the Pattern Repeat

The estimates above are for plain fabric. For a patterned fabric, add the repeat allowance on top: one full vertical repeat per cut length for a straight match, one and a half vertical repeats per cut length for a half drop. On a large-scale repeat this can add a significant proportion to the plain figure. The full method, with worked examples, is in our pattern matching guide.

The Rule That Prevents Shortfalls

Always have the upholsterer confirm the measured quantity against the specific frame before the fabric is ordered, and order the full quantity in one dye lot. A job that runs short mid-way needs a fresh order from a potentially different dye lot, which risks a visible colour difference and a programme delay. For dye lot management on larger orders, see our lead times and custom colour matching guide. For the full specification library organised by environment, application, and performance need, see our fabric buying guide by purpose.

Quick answers

How much fabric do I need to reupholster a sofa?
As a working estimate on 140 cm wide plain fabric, allow 10 to 14 metres for a two-seat sofa, 14 to 18 metres for a three-seat sofa, and 18 to 25 metres for a large or corner sofa. These are starting points for budgeting. A patterned fabric needs more to align the repeat, and a directional or pile fabric such as velvet needs more because of cutting restrictions. Always have the upholsterer confirm the measured quantity against the specific frame before ordering.

How much fabric to upholster a dining chair?
For a drop-in or fixed seat only, allow 0.5 to 0.75 metres of 140 cm wide plain fabric per chair. For a chair with an upholstered seat and back, allow 1.5 to 2 metres. Add a pattern-repeat allowance for patterned fabric, and order all chairs in a set from a single dye lot to avoid colour variation between them.

Why does a patterned fabric need more than a plain one?
A patterned fabric must be cut so the repeat aligns across every panel and seam, which means each cut length starts at the same point in the repeat and the fabric between those points is waste. Add one full vertical repeat per cut length for a straight match and one and a half for a half drop. On a large-scale repeat this can add a substantial proportion to the plain estimate.

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Mohair Velvet Faux Leather Cashmere Throws Silks Linen Textured Upholstery

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Buying Guide by Purpose Crib 5 Fire Guide Martindale Rub Test BS 5867 Curtains Marine Fabric

29 July 202614 August 2026

Fabric Buying Guide by Purpose: Specification Guides for Interior Designers

This guide indexes the KOTHEA fabric specification library by purpose. It is organised three ways: by the environment a fabric is specified for, by the application it is used in, and by the performance requirement that governs the selection. Each entry links to a full guide covering the standards, test methods, and specification detail for that subject. Use it to move from a project requirement to the relevant specification guidance without reading the library in sequence.

By environment

The environment a fabric is specified for determines the combination of fire standard, durability, cleaning compatibility, and light fastness that applies. The guides below cover the principal contract and residential environments.

Hotel and hospitality

Martindale thresholds by room type, BS 7176 Medium Hazard fire certification, cleaning regime compatibility, and dye lot consistency across phased projects are covered in the hotel fabric specification guide. For the thermal and moisture behaviour of mohair in hospitality use, see the mohair thermal properties guide.

Healthcare

Disinfectant cleaning compatibility, BS 7176 fire certification, 100,000 Martindale durability, and infection control are covered in the healthcare fabric specification guide.

Marine and yacht

The IMO FTP Code, MCA MGN 580, and why BS 5852 Crib 5 is not interchangeable with IMO Part 8 are covered in the IMO marine fire standards guide.

Outdoor terraces and semi-outdoor spaces

Exposure mapping, solution-dyed acrylic, outdoor-rated faux leather, and light fastness by location are covered in the outdoor terrace fabric specification guide.

Poolside, spa, and chlorine-exposed areas

Why chlorine degrades fabric by a different mechanism than salt and UV, and what to specify for pool and spa surrounds, are covered in the poolside and chlorine-exposed fabric guide.

Acoustic and home cinema

How heavy velvet absorbs mid and high frequency sound and functions as an acoustic treatment is covered in the velvet sound absorption guide.

Contract versus residential

Why contract grade is defined by performance rather than by building type, and when a residential project needs a contract specification, are covered in the contract versus residential guide.

By application

The application a fabric is used in sets the abrasion, drape, and construction requirements independently of the environment.

Upholstery

The Martindale rub test, its classifications, and how it compares to the Wyzenbeek standard are covered in the Martindale rub test guide and the Wyzenbeek versus Martindale guide. Pilling resistance is covered in the pilling resistance guide, and the tactile character of the principal upholstery fibres in the fabric hand and tactile properties guide.

Curtains

Pattern repeat calculation and matching for curtains and upholstery are covered in the pattern matching guide. The applications where velvet is unsuitable, including several curtain and window conditions, are covered in the when not to use velvet guide.

Wall panels and headboards

BS EN 13501-1, BS 476 Part 7, the composite testing requirement for wall fabric, and the headboard fire standard ambiguity are covered in the wall panels and headboards guide and the BS 476 Part 7 guide.

By performance need

Where a single performance requirement governs the selection, the guides below address it directly.

Fire certification

BS 5852 Crib 5 is covered in the Crib 5 guide. How FR treatment works and which fibres can be treated are covered in the how FR treatment works guide and the FR treatment and fibres guide. Dye and FR treatment compatibility is covered in the dye types and FR treatment guide. The Building Safety Act 2022 documentation requirements are covered in the Building Safety Act guide.

Chlorine, UV, and salt resistance

Chlorine exposure is covered in the poolside and chlorine-exposed fabric guide. Light fastness and UV fading are covered in the light fastness and Blue Wool Scale guide. Cold crack temperature performance for coated fabrics in exterior and marine use is covered in the cold crack temperature testing guide.

Colour fastness and matching

Colour fastness and crocking are covered in the colour fastness and crocking guide. Colour naming, systems, and metamerism are covered in the colour naming and specification guide.

Chemical compliance and sustainability

UK REACH compliance is covered in the REACH compliance guide. Sustainability certifications are covered in the fabric sustainability certifications guide. Cashmere and mohair welfare certification is covered in the cashmere and mohair welfare certifications guide. Faux leather sustainability is covered in the faux leather sustainability guide.

Material selection

Velvet types compared across every specification dimension are covered in the velvet types guide, with mohair and cotton velvet compared directly in our mohair velvet vs cotton velvet guide. Faux leather types are compared in the faux leather types guide, with PVC and PU compared directly in our PVC vs PU leather guide.

Procurement and project planning

How much fabric a chair, sofa, or headboard needs is estimated in the how much fabric to upholster furniture guide. Contract curtains, covering the BS 5867 fire standard, light control, and fullness, are specified in the contract curtain fabric specification guide. How to write a complete fabric specification and what certificates to require is set out in the how to write a fabric specification guide. Definitions of the terms used across these guides are collected in the fabric specification glossary. Which fabric decision belongs at each project stage is covered in the RIBA Plan of Work fabric guide. Lead times, cuttings, dye lot reservation, and custom colour matching are covered in the lead times, cuttings and custom colour matching guide.

Quick answers

How do I choose the right fabric for a contract project?
Start from the governing requirement. Where a single environment sets the specification, such as a hotel, healthcare, marine, or poolside setting, the environment guide covers the full combination of fire, durability, cleaning, and light fastness standards that apply. Where a single performance requirement governs, such as fire certification or chlorine resistance, the relevant performance guide addresses it directly. Confirm the fire standard, Martindale threshold, cleaning code, and light fastness grade for the specific application before selecting a fabric.

What fire standard does my project need?
For most UK contract upholstery the standard is BS 7176 Medium Hazard, which incorporates BS 5852 Crib 5. Marine interiors follow the IMO FTP Code under MCA MGN 580, which is not interchangeable with Crib 5. Wall panels and headboards may fall under BS 476 Part 7 or BS EN 13501-1 depending on construction. The fire certification guides linked above cover each standard and when it applies.

How do I request samples of KOTHEA fabric?
Request cuttings of any KOTHEA fabric at KOTHEA.com/cuttings. Request cuttings early in the selection process, and where a scheme depends on several fabrics together, request cuttings of all of them so the combination can be assessed under the project’s lighting conditions before specification is finalised.

To request cuttings from the KOTHEA range, visit KOTHEA.com/cuttings.

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Order cutting samples of any fabric from our current collections. Trade accounts only.

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Our Collections

Mohair Velvet Faux Leather Cashmere Throws Silks Linen Textured Upholstery

Specification Guides

Buying Guide by Purpose Crib 5 Fire Guide Martindale Rub Test BS 5867 Curtains Marine Fabric

29 July 202629 July 2026

Lead Times, Cuttings and Custom Colour Matching for Commercial Projects

Cuttings first: Request cuttings early to confirm colour, handle, and quality before the fabric is committed to a scheme.
Dye lots: Fabric colour varies between dye lots. A large or phased contract order must be secured against dye lot variation from the outset.
Lead times vary by fabric type: Stock fabric ships quickly; woven-to-order, treated, and bespoke-colour fabric carries longer and more variable lead times.
Plan backwards: Work back from the installation date through treatment, weaving, and cutting-approval stages to establish when the order must be placed.

The operational side of fabric specification, cuttings, lead times, dye lots, and custom colour, is where contract projects most often encounter avoidable delay and cost. A fabric selected correctly on performance can still cause a problem if the lead time is not understood, the dye lot is not secured, or a custom colour is commissioned without allowing for the approval process. This guide sets out the practical sequence for managing fabric procurement on a commercial project.

For the stage at which each fabric decision belongs in a project, see our RIBA Plan of Work fabric guide. To request cuttings, visit KOTHEA.com/cuttings.

Cuttings: Confirming the Fabric Before Commitment

A cutting is a physical sample of the actual fabric, and it is the only reliable way to confirm colour, handle, texture, and quality before committing a fabric to a scheme. Screen and print representations of fabric colour are unreliable: a colour on a monitor or a printed colour card differs from the real fabric because of the difference between emitted and reflected colour and the effect of the fabric’s texture and pile on how it reflects light.

Request cuttings early in the selection process, while there is still time to consider alternatives. A cutting confirms not only the colour but the hand of the fabric, how it drapes, the character of the pile or weave, and the quality of the construction. For a contract project these should be confirmed against the actual fabric before specification is finalised, not assumed from a colour card.

Where a scheme depends on the relationship between several fabrics, request cuttings of all of them together so the combination can be assessed as it will appear in situ. Colours that work individually on separate cards may relate differently when the actual fabrics are seen side by side under the project’s lighting conditions.

Dye Lots and Why They Matter for Contract Orders

Fabric is dyed in batches, and each batch is a dye lot. Colour varies slightly between dye lots even for the same fabric and colourway, because the dyeing process cannot be replicated with perfect precision from one batch to the next. For a small residential order cut from a single roll this is rarely an issue. For a contract order it can be a significant problem.

A large contract order that draws fabric from more than one dye lot risks visible colour variation between pieces of furniture, between runs of curtains, or between panels that are seen together. A phased project, where fabric is ordered at intervals as the installation progresses, risks later phases being supplied from a different dye lot than earlier phases.

The way to manage this is to secure sufficient fabric from a single dye lot at the outset to cover the whole requirement, including a wastage and future-repair allowance. Where a project is phased, discuss dye lot reservation with the supplier at the point of first order so that later phases can be supplied from the same lot or from a reserved allocation. This must be arranged in advance; it cannot be corrected once the initial dye lot is exhausted.

Lead Times by Fabric Type

Lead time varies substantially by fabric type, and understanding the difference is essential to project scheduling.

Stock fabric. Fabric held in stock in the required colourway ships in the shortest time, typically limited only by order processing and delivery. This is the fastest route but is available only where the specific fabric and colourway are held in sufficient quantity.

Woven-to-order fabric. Fabric that is woven to order rather than held in stock carries a manufacturing lead time. For handwoven and specialist fabrics this can be a matter of weeks. The cashmere throws, for example, are handwoven to order with a lead time of approximately two to three weeks from order confirmation. Woven-to-order lead times must be built into the project programme from the point of specification.

FR-treated fabric. Fabric requiring topical flame-retardant treatment carries the treatment lead time in addition to the fabric lead time. The fabric must be sourced, sent for treatment, treated, tested, and certified before it can be installed. Each stage takes time and the testing and certification stage in particular cannot be compressed. For contract projects requiring treated fabric, the treatment lead time is often the critical path item.

Bespoke-colour fabric. Fabric woven or dyed to a custom colour carries the longest and most variable lead time because it combines a colour-matching approval process with a manufacturing run.

Custom Colour Matching

Custom colour matching allows a fabric to be produced in a specific colour to suit a scheme, rather than selecting from the standard colourways. It is a valuable capability for contract projects with a defined palette, but it carries a process that must be allowed for in the programme.

The process begins with a colour reference, ideally a physical sample rather than a screen or print colour, since the same considerations apply as for cuttings. The mill produces a lab dip or strike-off, a small sample of the fabric dyed to the target colour, for approval. This is assessed against the reference, and if it is not correct the mill produces a revised dip. This approval cycle may take one or more iterations, each of which takes time.

Once the colour is approved, the fabric is woven or dyed to order in the approved colour, which is a manufacturing lead time on top of the approval process. There is usually a minimum order quantity for a bespoke colour, since the mill is setting up a production run for a specific requirement.

For a contract project, custom colour matching should be initiated as early as possible once the palette is confirmed, because the approval cycle plus the manufacturing run makes it the longest-lead item in most fabric procurement. Confirm the expected number of approval iterations, the minimum order quantity, and the total lead time with the supplier before committing to a bespoke colour, so the programme can accommodate it.

Planning the Procurement Sequence

The reliable way to avoid fabric-related delay on a contract project is to work backwards from the installation date. Establish when the fabric must be on site, then work back through each stage that applies to the specific fabric: installation, delivery, treatment and certification if required, manufacturing or weaving, custom colour approval if required, and cutting approval. The sum of these stages gives the latest date by which the order must be placed.

For a stock fabric in a standard colourway with no treatment requirement, this sequence is short. For a bespoke-colour, FR-treated, woven-to-order fabric, it can extend to several months, and each stage depends on the one before it. Identifying the critical path early, and placing the order to accommodate it, is the single most effective way to prevent fabric from delaying a project.

Quick answers

Why should I request cuttings before specifying a fabric?
A cutting is a physical sample of the actual fabric and is the only reliable way to confirm colour, handle, texture, and quality before committing it to a scheme. Screen and printed colour representations are unreliable because emitted and reflected colour differ and because a fabric’s texture and pile affect how it reflects light. Request cuttings early, and where a scheme depends on several fabrics together, request cuttings of all of them so the combination can be assessed as it will appear in situ.

What is a dye lot and why does it matter for contract orders?
Fabric is dyed in batches, and each batch is a dye lot. Colour varies slightly between dye lots because dyeing cannot be replicated with perfect precision from batch to batch. For a large contract order drawing from more than one dye lot, this risks visible colour variation between pieces seen together. Secure sufficient fabric from a single dye lot at the outset to cover the whole requirement plus a repair allowance, and for phased projects arrange dye lot reservation with the supplier at first order.

How long does FR-treated fabric take to supply?
FR-treated fabric carries the treatment lead time in addition to the fabric lead time. The fabric must be sourced, sent for treatment, treated, tested, and certified before installation. The testing and certification stage in particular cannot be compressed. For contract projects requiring treated fabric, the treatment lead time is often the critical path item, so it should be identified and built into the programme from the point of specification rather than assumed to be a short additional step.

How does custom colour matching work?
Custom colour matching begins with a colour reference, ideally a physical sample. The mill produces a lab dip or strike-off, a small sample dyed to the target colour, for approval against the reference. If it is not correct, a revised dip is produced, and this approval cycle may take several iterations. Once approved, the fabric is woven or dyed to order, which is a manufacturing lead time on top of the approval process, usually with a minimum order quantity. It is typically the longest-lead item in fabric procurement.

How far in advance should I order fabric for a commercial project?
Work backwards from the installation date through each stage that applies to the specific fabric: installation, delivery, treatment and certification if required, manufacturing or weaving, custom colour approval if required, and cutting approval. For a stock fabric in a standard colourway this sequence is short. For a bespoke-colour, FR-treated, woven-to-order fabric it can extend to several months, with each stage dependent on the one before. Identify the critical path early and place the order to accommodate it.

For the project stage at which each fabric decision belongs, see our RIBA Plan of Work fabric guide. For hotel and hospitality specification including dye lot strategy, see our hotel fabric specification guide. To request cuttings from the KOTHEA range, visit KOTHEA.com/cuttings.

Request Samples

Order cutting samples of any fabric from our current collections. Trade accounts only.

Order Cuttings

Our Collections

Mohair Velvet Faux Leather Cashmere Throws Silks Linen Textured Upholstery

Specification Guides

Buying Guide by Purpose Crib 5 Fire Guide Martindale Rub Test BS 5867 Curtains Marine Fabric

6 April 202628 July 2026

The Building Safety Act 2022 and Fabric Specification: What Interior Designers Need to Know

What the Act introduced: A Principal Designer role with legal duties to ensure all design work — including material specification — complies with Building Regulations. Operative from 1 October 2023 for all projects requiring building control approval.
Higher-risk buildings: Residential buildings 18 metres or more in height, or seven or more storeys. Additional, more stringent duties apply to all design work on these buildings.
What this means for fabric specification: Any designer specifying materials in a higher-risk building must be able to demonstrate competence in fire safety compliance. Every fabric specification decision that affects fire safety must be documented and retained as part of the building’s safety case.
Who this applies to: Interior designers, architects, and design-and-build contractors involved in any project requiring building control approval in England.

The Building Safety Act 2022 is the most significant change to the regulation of building design and construction in England since the 1980s. It was enacted in response to the Grenfell Tower disaster and introduced a comprehensive new duty-holder framework, new competence requirements, and a new regulatory body — the Building Safety Regulator (BSR) — with powers to scrutinise and approve higher-risk building work. Interior designers and fabric specifiers are affected by the Act in ways that are not always clearly communicated. This guide explains what the Act requires, what it means for fabric specification decisions, and how to document compliance.

What the Building Safety Act 2022 Does

The Act creates a new regulatory regime for all building work requiring building control approval in England, with additional and more stringent requirements for higher-risk buildings. It does three things relevant to interior designers and fabric specifiers.

First, it introduces a mandatory Principal Designer role for any project with more than one contractor, operative from 1 October 2023. The Principal Designer is responsible for planning, managing, monitoring, and coordinating the design work to ensure compliance with Building Regulations — including fire safety. This is a distinct role from the Principal Designer under CDM Regulations 2015, although the same person or organisation may hold both roles if competent to do so.

Second, it places a duty of competence on anyone carrying out design work. Section 35 of the Act defines competence as having the necessary skills, knowledge, experience, and behaviours. A designer who specifies materials — including fabrics and soft furnishings — in a building subject to the Act must be able to demonstrate that their specification decisions comply with the applicable Building Regulations fire safety requirements.

Third, it introduces a golden thread of information — a continuous, maintained record of design decisions relating to fire safety and structural integrity — that must be created during the design phase, updated through construction, and retained for the life of the building. For higher-risk buildings this is a formal legal requirement. For other buildings the principle of maintaining clear documentation of safety-related design decisions is strongly recommended and increasingly expected by the insurance market.

Higher-Risk Buildings: What They Are and Why They Matter

A higher-risk building (HRB) is defined under the Act as a building of at least 18 metres in height or at least seven storeys, containing at least two residential units. Most tall residential apartment buildings in England meet this definition. Many hotel developments, residential care buildings, and mixed-use developments with residential components also qualify.

For HRB projects, the Building Safety Regulator must approve the design before construction begins at Gateway 2. The Principal Designer must submit a detailed compliance statement demonstrating that the design meets Building Regulations requirements. All duty holders — including designers — must operate a mandatory occurrence reporting system and report any safety occurrence to the BSR.

A safety occurrence is defined as any aspect of the design relating to the structural integrity or fire safety of a higher-risk building that, if built, would present a significant risk of death or serious injury. A fabric specification that does not meet the applicable fire standard — or that uses a topical FR treatment that has degraded without replacement — could in principle constitute a safety occurrence in an HRB context. This is not a theoretical risk. It is the kind of documentation failure that the golden thread requirement is specifically designed to prevent.

What This Means for Fabric Specification

For most interior design projects, the Building Safety Act’s practical impact on fabric specification is not a change in the fire standards that apply — Crib 5, BS 7176, BS 5867 were the applicable standards before the Act and remain so — but a change in the documentation and accountability requirements around compliance with those standards.

Before the Act, a designer who specified a Crib 5-certified fabric for a hotel project was meeting the applicable fire standard. After the Act, that same designer must also be able to demonstrate: that they understood the applicable standard and specified correctly against it; that they obtained a valid test certificate from a UKAS-accredited laboratory; that they documented the specification decision and retained the certificate; and, if the project involves an HRB, that the fabric specification was included in the golden thread information provided to the Principal Designer and ultimately to the building owner.

The practical implication is that fabric specification documentation must be more systematic than it often has been. A verbal instruction to the upholsterer or a purchase order without fire certification reference is no longer adequate for projects subject to the Act. The fire test certificate must be obtained before installation, referenced in the specification document, and retained as part of the project file.

For full guidance on obtaining fire test certificates and what they must cover, see our Crib 5 guide, our hotel fabric specification guide, and our FR treatment guide.

The Principal Designer Role and Interior Design Services

The RIBA/BIID professional services contracts — updated in their 2024 amendments — include an expanded schedule of services that now explicitly references the Principal Designer role under Part 2A of the Building Regulations. An interior designer or architect carrying interior design services within their scope on a qualifying project may be asked to act as, or contribute to the duties of, the Principal Designer.

The 2024 amendment to the RIBA/BIID contracts draws specific attention to the requirement for the designer to assess their competency to undertake the Principal Designer role before accepting it. Interior designers whose practice includes projects in higher-risk buildings should assess whether their competence in fire safety, structural safety, and the golden thread documentation requirements meets the standard required by PAS 8671, the publicly available specification setting out the minimum competence requirements for Principal Designers.

The Golden Thread and Fabric Documentation

The golden thread is a digitally maintained record of design decisions relating to fire safety and structural integrity. For fabric specification in a higher-risk building, it should contain the following for each fire-safety-relevant fabric decision. The fabric description — supplier, range name, colourway, width, and fibre composition. The fire standard the fabric is certified against — BS 7176 Medium or High Hazard, BS 5867 Part 2 Type B or C, or equivalent. The test certificate reference number and the name of the UKAS-accredited laboratory that issued it. The filling and interliner specified with the fabric, as the certificate covers the assembly rather than the face fabric alone. The date of installation and the location within the building. Any re-treatment or re-certification requirement and the recommended review date.

Building this documentation into the fabric specification process at Stage 3 of the RIBA Plan of Work — when specific fabrics are selected and technical data sheets are obtained — adds minimal time and significantly strengthens both legal compliance and the designer’s professional liability position. For guidance on fabric decisions at each RIBA stage, see our RIBA Plan of Work fabric guide.

Liability and the 30-Year Limitation Period

A 2025 Supreme Court ruling in URS Corporation Ltd v BDW Trading Ltd interpreted section 135(3) of the Building Safety Act to extend the limitation period for negligence claims relating to building safety from six to thirty years, including retrospective claims. This means that design decisions made today — including fabric specification decisions that affect fire safety in higher-risk buildings — could be subject to legal challenge for up to thirty years.

The practical implication for fabric specifiers is that the documentation of fire compliance at the time of specification — the fire test certificate, the specification schedule, the installation record — is evidence of due diligence that may need to be relied upon many years after practical completion. Maintaining systematic records of fire certification for all higher-risk building fabric specification decisions is strongly advisable.

What Interior Designers Should Do

Review your specification documentation process and confirm that it captures fire test certificate references, UKAS-accredited laboratory names, and filling and interliner details for every fabric specified in a fire-safety-relevant position. This applies to all contract projects, not only those classified as higher-risk buildings.

For any project that may involve an HRB — a residential building of seven or more storeys or 18 metres or more in height — seek advice from the Principal Designer appointed on the project about what fabric documentation is required as part of the golden thread. If you are the party being asked to act as Principal Designer, assess your competence against PAS 8671 before accepting the role.

Ensure your professional indemnity insurance covers the scope of design services you are providing on BSA-affected projects. The Act has introduced new and more extensive liabilities for designers, and cover that was adequate before 1 October 2023 may need to be reviewed.

When specifying fabric for fire-safety-relevant positions in higher-risk buildings, prefer inherently fire-resistant fabrics over those requiring topical FR treatment. Inherent fire resistance does not degrade with cleaning or over time and does not require re-certification during the building’s life. See our FR treatment and fibre compatibility guide for guidance on which fabrics carry inherent certification.

Quick answers

Does the Building Safety Act apply to all interior design projects?
The duty-holder framework applies to all projects requiring building control approval in England where there is more than one contractor, from 1 October 2023. The additional and most stringent requirements apply to higher-risk buildings — residential buildings of at least 18 metres in height or at least seven storeys containing two or more residential units. Most interior refurbishment projects of individual apartments do not require building control approval and are not directly caught by the Act. Commercial fit-outs, whole-building refurbishments, and new build projects with residential use at seven or more storeys are more likely to be affected.

What fire standards apply to fabric in higher-risk buildings?
The Building Safety Act does not introduce new fire standards for fabrics. The applicable standards remain BS 7176 for upholstered seating, BS 5867 for curtains, and the Regulatory Reform (Fire Safety) Order 2005 for the responsible person’s ongoing fire safety obligations. What the Act changes is the documentation and accountability requirements around compliance with those standards — specifically the requirement to maintain a golden thread of fire safety design decisions for higher-risk buildings.

What is the golden thread and what fabric information does it need to contain?
The golden thread is a digitally maintained record of design decisions relating to fire safety and structural integrity. For fabric specification in a higher-risk building, it should contain the fabric description, the fire certification standard and certificate reference, the UKAS-accredited laboratory name, the filling and interliner details, the date and location of installation, and any re-treatment requirements. This information must be maintained for the life of the building.

Can an interior designer be the Principal Designer under the Building Safety Act?
Yes, if they have the necessary competence as defined by PAS 8671. An interior designer appointed as lead designer on a project with more than one contractor must assess whether their competence in fire safety, structural safety, and documentation management meets the standard required. For HRB projects, the competence requirements are more demanding and formal competence assessment against PAS 8671 is advisable before accepting the appointment.

For fire certification standards and test certificates, see our Crib 5 guide. For fabric documentation at each RIBA Plan of Work stage, see our RIBA Plan of Work fabric guide. For FR treatment and inherent fire resistance, see our FR treatment and fibre compatibility guide.

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6 April 202628 July 2026

BS 476 Part 7: Surface Spread of Flame for Wall and Ceiling Linings

What it tests: How quickly flame spreads across the surface of a material when exposed to a heat source. Relevant to wall panels, ceiling linings, acoustic panels, and fabric wall coverings.
The four classes: Class 1 is the most restrictive — very limited spread of flame. Class 4 is the least restrictive. Class 0 is a composite designation covering Class 1 surface spread of flame plus a non-combustibility requirement.
What it does not test: Upholstery fire performance. BS 476 Part 7 is a surface lining test, not an upholstery test. Crib 5 and BS 7176 cover upholstered seating.
Who requires it: Building control for non-domestic buildings; the Regulatory Reform (Fire Safety) Order 2005 for occupied non-domestic premises.

Interior designers specifying fabric for wall panels, acoustic panels, and decorative wall linings in commercial environments need to understand BS 476 Part 7 alongside the upholstery fire standards. Where Crib 5 and BS 7176 cover the fire performance of upholstered seating, BS 476 Part 7 covers how quickly flame spreads across surfaces — walls, ceilings, and the materials covering them. The two standards address different fire risks and apply to different elements of an interior specification.

What BS 476 Part 7 Tests

BS 476 Part 7 is the British Standard method for testing the surface spread of flame of building products. It measures how far and how fast a flame travels across the surface of a material when one end is exposed to a defined heat source. The test is conducted on a sample 900 mm long by 225 mm wide, mounted vertically on a radiant heat panel. A pilot flame is applied at one end and the spread of flame along the sample is measured at 90 seconds, 3 minutes, and 10 minutes from ignition.

The results determine which of the four BS 476 Part 7 classes the material achieves. The test is separate from, and not interchangeable with, the upholstery tests. A fabric that passes BS 476 Part 7 Class 1 is certified for use as a surface lining material. This certification says nothing about its performance as an upholstery fabric under Crib 5 or BS 7176 ignition sources.

The Four Classes

Class 1 is the most restrictive classification. Flame spread at 90 seconds must not exceed 165 mm and at 10 minutes must not exceed 165 mm. Class 1 is required for walls and ceilings in most circulation areas, corridors, stairways, and escape routes in non-domestic buildings under the Building Regulations. For fabric wall panels in commercial interiors, Class 1 is the specification that most building control officers and fire risk assessors will expect in occupied non-domestic premises.

Class 0 is not defined within BS 476 Part 7 itself. It is a composite classification used in Approved Document B requiring Class 1 surface spread of flame and additionally meeting non-combustibility or limited combustibility requirements to BS 476 Part 11 or Part 4. Most fabric materials cannot achieve Class 0. Glass fibre and mineral fabrics can. For most commercial interior projects, Class 1 is the practical target for fabric wall linings.

Class 2 is acceptable for wall linings in lower-risk areas of some non-domestic buildings where Class 1 is not explicitly required. In practice, specifiers should aim for Class 1 across commercial interiors to provide a consistent and defensible specification.

Class 3 is the minimum permitted for wall linings in domestic rooms and some low-risk areas of non-domestic buildings under Approved Document B. Not appropriate for escape routes, corridors, or high-occupancy commercial spaces.

Class 4 does not meet any acceptable Building Regulations standard for wall or ceiling linings in habitable spaces.

BS EN 13501-1: The European Equivalent

The European reaction to fire classification system, BS EN 13501-1, uses Euroclass ratings — A1, A2, B, C, D, E, F — with additional designations for smoke production and flaming droplet behaviour. BS 476 Part 7 Class 1 is approximately equivalent to Euroclass B or C. BS 476 Part 7 Class 0 is approximately equivalent to Euroclass B with s1, d0 designations. These are not exact equivalences.

For wall panel and acoustic panel fabric specification in the UK, it is safest to request a BS 476 Part 7 test result specifically from the supplier rather than relying on Euroclass conversion, unless the building control officer for the specific project has confirmed acceptance of Euroclass ratings as equivalent.

Fabric Applications Requiring BS 476 Part 7

Fabric-covered wall panels, whether fixed directly to the wall or suspended on a batten system, form a wall lining. The fabric and any interliner or backing material must be tested together as the composite assembly. A fabric that achieves Class 1 as a face fabric may not achieve Class 1 when applied over a foam interliner, because the combined assembly’s performance depends on all layers.

Acoustic fabric panels installed on walls for sound absorption purposes are wall linings and require BS 476 Part 7 classification. The acoustic infill material — typically mineral wool or acoustic foam — affects the composite panel’s classification. Mineral wool infill is non-combustible. Polyurethane acoustic foam typically achieves Class 2 or 3 at best and will limit the composite panel’s classification accordingly.

Fabric wall coverings applied over plaster or plasterboard similarly form a wall lining. The surface to which the fabric is applied affects the test result, so the fabric should be tested in the configuration as installed.

Headboards in hotel bedrooms are treated as furniture rather than wall linings and are therefore subject to the upholstery standards — Crib 5 and BS 7176 — rather than BS 476 Part 7. For full guidance on headboard specification, see our wall panels and headboards guide.

Achieving Class 1 with Fabric

Most uncoated natural-fibre fabrics will not achieve BS 476 Part 7 Class 1 without topical FR treatment. Cotton, linen, and viscose fabrics ignite readily and will typically achieve only Class 3 or Class 4 without treatment. Wool and mohair have significantly better inherent fire resistance but still typically require treatment to achieve Class 1 for wall lining applications.

Topical FR treatment — typically wet-padding with intumescent or phosphorus-based compounds — can raise most cellulosic fabrics from Class 3 or 4 to Class 1. The treatment must be applied by a UKAS-accredited treatment company and the treated assembly must be tested as a composite with the backing and fixings used in the actual installation. For guidance on FR treatment and dye interaction risks, see our dye types and FR treatment guide.

Some polyester fabrics with inherent flame retardant additives — including Trevira CS — can achieve Class 1 without topical treatment, with better long-term durability than treated natural-fibre fabrics.

Testing and Certification

BS 476 Part 7 certificates must be issued by a UKAS-accredited testing laboratory. A supplier’s own claim that a fabric meets Class 1 is not sufficient for building control purposes. The certificate should specify the fabric tested, the configuration tested including backing materials and fixings, the test standard, and the classification achieved.

For composite wall panel systems, the certificate should cover the full assembly rather than the face fabric in isolation. Testing the face fabric alone and assuming the assembly will achieve the same classification is not reliable.

Certificates should be retained for the life of the installation and included in the building’s fire safety documentation. For projects subject to the Building Safety Act 2022, the classification certificates for all wall lining materials form part of the golden thread. See our Building Safety Act guide for documentation requirements.

Quick answers

What is the difference between BS 476 Part 7 and BS 5852 Crib 5?
BS 476 Part 7 tests surface spread of flame on wall and ceiling lining materials. BS 5852 Crib 5 tests the fire resistance of upholstered seating assemblies. They test different products under different fire scenarios and one certification does not substitute for the other. A fabric certified to BS 476 Part 7 Class 1 for wall panel use requires separate Crib 5 testing if it is also to be used for upholstered seating in the same project.

Do headboards in hotel rooms need BS 476 Part 7 certification?
No. Headboards are classified as furniture and are subject to BS 5852 and BS 7176, not the surface lining standards. A headboard fixed to the wall does not become a wall lining by being attached. Confirm the applicable standard with the building control officer or fire risk assessor for the specific project if there is any doubt.

What does Class 0 mean and can fabric achieve it?
Class 0 is a composite designation in the Building Regulations requiring Class 1 surface spread of flame and additionally meeting non-combustibility or limited combustibility requirements. Most fabric materials cannot achieve Class 0. Glass fibre and mineral fabrics can. For most commercial interior projects, Class 1 is the practical target for fabric wall linings.

Does the fabric or the whole wall panel assembly need to be tested?
The whole assembly — face fabric, interliner, backing, and fixing method — should be tested together. Testing the face fabric in isolation and assuming the composite assembly will achieve the same classification is unreliable, because the thermal behaviour of backing materials significantly affects the test result.

How does BS 476 Part 7 relate to BS EN 13501-1?
BS EN 13501-1 is the European reaction to fire classification using Euroclasses A1 to F. BS 476 Part 7 Class 1 is approximately equivalent to Euroclass B or C, though the equivalence is not exact. For UK projects, always request BS 476 Part 7 results specifically unless the building control officer has confirmed acceptance of Euroclass ratings for the specific project.

For wall panel and headboard fire specification, see our wall panels and headboards guide. For upholstery fire standards, see our Crib 5 guide. For FR treatment guidance, see our FR treatment and fibre compatibility guide.

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6 April 202628 July 2026

Wyzenbeek vs Martindale: Which Abrasion Test Should You Specify?

Martindale: The standard used in the UK and Europe. Fabric is rubbed in a figure-of-eight motion against a worsted wool abradant. Results in rub counts. Contract minimum 30,000 rubs.
Wyzenbeek: The standard used in the United States. Fabric is rubbed back and forth in straight lines against a cotton duck canvas abradant. Results in double rubs. Contract minimum 15,000 double rubs.
Are they comparable? No. The two tests use different abradants, different motions, and different pass criteria. A Wyzenbeek double rub count cannot be converted to a Martindale rub count.
Which to specify: For UK and European projects, always specify Martindale. For US projects, specify Wyzenbeek. For international projects, request both where possible.

Interior designers working internationally, or sourcing fabric from American suppliers, regularly encounter both Martindale rub counts and Wyzenbeek double rub counts on specification sheets. The two figures look similar — both express abrasion resistance as a number — but they are produced by entirely different test methods and cannot be meaningfully compared. Specifying a Wyzenbeek result on a UK contract project, or a Martindale result on a US project, risks misaligned expectations with clients, contractors, and insurers. This guide explains how each test works, what the results mean, and how to specify correctly for UK and international projects.

The Martindale Test

The Martindale abrasion test is defined by ISO 12947 and BS EN ISO 12947. It is the standard abrasion test used across the UK, Europe, and most international markets outside the United States. When a fabric data sheet lists a rub count without specifying the test method, the default assumption in UK specification is Martindale.

The test works as follows. A circular sample of the fabric being tested is mounted face-down on a machine and rubbed against a standard abradant — a piece of worsted wool fabric — in a figure-of-eight motion that moves the sample across the abradant in all directions simultaneously. This multidirectional motion is designed to replicate the complex, non-linear abrasion that upholstery fabric experiences in real use. The machine counts each complete figure-of-eight cycle as one rub.

The test is run to one of several endpoints. The most common endpoint for upholstery fabrics is fabric breakdown — the point at which two threads have broken or a hole has appeared in the sample. Some test houses also assess and report pilling at intermediate intervals using a separate grading scale. The total rub count at breakdown is the Martindale rub count reported on the data sheet.

For a complete guide to Martindale thresholds by application and what the numbers mean in practice, see our Martindale rub test guide.

The Wyzenbeek Test

The Wyzenbeek abrasion test is defined by ASTM D4157, the American Society for Testing and Materials standard. It is the dominant abrasion test in the US contract furniture and upholstery market. UK designers sourcing fabric from American suppliers, or specifying for projects with US compliance requirements, will encounter Wyzenbeek results on data sheets.

The test works as follows. A rectangular sample of the fabric being tested is mounted on a machine and rubbed back and forth in straight lines — first in the warp direction, then in the weft direction — against a standard abradant. The standard abradant specified by ASTM D4157 is cotton duck canvas, a tightly woven plain-weave cotton fabric significantly more abrasive than the worsted wool used in Martindale. Each complete back-and-forth cycle counts as one double rub.

The Wyzenbeek test runs until the fabric shows noticeable wear or breakdown, and the double rub count at that point is reported. The linear back-and-forth motion differs fundamentally from the multidirectional figure-of-eight motion of Martindale, which is why the two tests produce results that cannot be directly compared.

Why the Results Cannot Be Compared

The most important point for a specifier to understand is that 50,000 Martindale rubs and 50,000 Wyzenbeek double rubs do not represent the same level of abrasion resistance. They are measurements from different instruments using different abradants, different motion patterns, and assessed against different pass criteria.

The cotton duck canvas abradant used in Wyzenbeek is more aggressive than the worsted wool abradant used in Martindale. All else being equal, a fabric tested to Wyzenbeek will reach its endpoint faster than the same fabric tested to Martindale, because the abradant is harsher. This means Wyzenbeek counts tend to be lower than Martindale counts on equivalent fabrics.

However, this relationship is not consistent across all fabric types. Different fibres and constructions respond differently to the two abradants and the two motion patterns. There is no reliable conversion factor between Wyzenbeek double rubs and Martindale rubs. Various informal conversion ratios circulate in the trade — most commonly the suggestion that one Wyzenbeek double rub equals approximately two Martindale rubs — but this ratio has no scientific basis and should not be relied upon for specification.

The only reliable way to compare two fabrics on a like-for-like basis is to ensure both have been tested to the same standard. When building a specification, always confirm which test method produced the figures on the data sheet.

UK and European Thresholds: Martindale

The following thresholds represent current UK and European contract specification practice for Martindale rub counts. For full detail on each threshold and the reasoning behind it, see our Martindale rub test guide.

Light domestic use: 15,000 rubs minimum. Heavy domestic use: 25,000 rubs minimum. Light contract: 30,000 rubs minimum. General contract — hotel lobbies, restaurant seating, office seating: 50,000 to 60,000 rubs. Heavy contract: 80,000 to 100,000 rubs. Severe contract: 100,000 rubs and above.

US Thresholds: Wyzenbeek

The following thresholds are used in the US contract market for Wyzenbeek double rubs. They are not equivalent to the Martindale thresholds above and should not be compared directly.

Residential use: 9,000 to 15,000 double rubs minimum. Light commercial: 15,000 double rubs minimum. Heavy commercial — hotels, restaurants, office seating: 30,000 to 50,000 double rubs. Severe commercial: 100,000 double rubs.

Which Test to Specify and When

For any project in the UK or continental Europe, always specify Martindale to ISO 12947. This is the expected standard, the one UK test houses use, and the one UK and European contract furniture manufacturers certify their fabrics against. If a fabric supplier provides only a Wyzenbeek result and cannot provide a Martindale result, request that the fabric be tested to Martindale before specifying it for a UK contract project.

For projects in the United States, specify Wyzenbeek to ASTM D4157. For international hospitality projects drawing from both European and American suppliers, request both test results where possible and compare within the same test method rather than across methods.

For yacht and marine projects, the fire standard takes precedence over abrasion performance. See our IMO marine fire standards guide.

Pilling: A Separate Test

Both Martindale and Wyzenbeek measure abrasion resistance — structural wear of the yarn. Neither measures pilling resistance, which is the formation of surface fibre balls through tangling of loose fibre ends. Pilling is assessed by a separate test, ISO 12945-2, also run on the Martindale machine but using a different abradant and a different assessment scale. A fabric with an excellent Martindale abrasion count may still pill badly in use. Always request both the Martindale abrasion result and the ISO 12945-2 pilling grade for contract upholstery specification. See our pilling resistance guide.

Quick answers

What is the difference between Martindale and Wyzenbeek?
Martindale rubs the fabric sample in a multidirectional figure-of-eight motion against a worsted wool abradant, counting each cycle as one rub. Wyzenbeek rubs the fabric back and forth in straight lines against a cotton duck canvas abradant, counting each back-and-forth cycle as one double rub. The abradants, motions, and pass criteria are different. The results cannot be directly compared.

Can I convert Wyzenbeek double rubs to Martindale rubs?
No reliable conversion factor exists. Informal ratios circulate in the trade but have no scientific basis and produce unreliable results across different fabric types. The only reliable approach is to test the same fabric to both standards.

What Martindale count should I specify for a hotel?
For hotel bedroom seating: 30,000 rubs minimum. For hotel restaurant and lobby seating: 50,000 to 60,000 rubs. For hotel bar and high-traffic areas: 80,000 to 100,000 rubs. See our hotel fabric specification guide for full detail.

Is Wyzenbeek used in the UK?
Wyzenbeek is not the standard abrasion test in the UK. Martindale to ISO 12947 is the expected test for UK and European contract specification. Wyzenbeek results may appear on data sheets from American suppliers. Always confirm which test standard produced the figures before using them in a UK specification.

What abradant does Martindale use?
The standard Martindale abradant for upholstery fabric testing is worsted wool fabric to ISO 12947-2. Results against different abradants are not directly comparable. Always confirm the abradant used when reviewing a Martindale certificate.

For Martindale thresholds by application, see our Martindale rub test guide. For pilling resistance, see our pilling resistance guide. For hotel specification, see our hotel fabric specification guide.

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6 April 202611 April 2026

Top UK Interior Designers 2026: London and National

The following is a curated reference list of interior design studios and practitioners active in the UK in 2026, compiled for homeowners, property developers, and clients seeking design representation for residential and commercial projects. The list is organised by location — London studios first, followed by national coverage — and listed alphabetically within each section. No ranking is implied. All studios listed were active and accepting new commissions at the time of compilation.

Kothea is a trade-only supplier of luxury fabrics based in London. We supply fabric directly to interior designers and architects. If you are a homeowner seeking a designer, the studios below can advise on the full range of fabric options available through trade accounts.

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London Studios

Beata Heuman. Stockholm-born, London-based, Beata Heuman’s studio produces interiors of playful sophistication — bold colour, idiosyncratic furniture, and a distinctive blend of Scandinavian restraint with maximal personality. Her residential work has been widely published and her aesthetic is among the most recognisable in contemporary London design. Website: beataheuman.com

BradyWilliams. Founded by Shayne Brady and Emily Williams, BradyWilliams offers a comprehensive bespoke interior design service for residential and commercial clients. Known for acute detailing, timeless design, and strong project management, the studio operates across London and internationally. Website: studioshaynebrady.com

Buchanan Studio. Led by Jessica Maybury, Buchanan Studio specialises in high-end residential projects with an emphasis on craftsmanship, natural materials, and considered materiality. The studio’s work has a quiet confidence and a strong understanding of bespoke joinery and architectural detail. Website: buchanan.studio

David Collins Studio. One of London’s most established luxury design studios, founded in 1985. The studio — now led by Iain Watson and Simon Rawlings — has defined interiors at iconic London locations and continues to work across hospitality, retail, and high-end residential. Known for layered palettes and architectural precision. Website: davidcollins.studio

Design Haus Liberty. Founded by Dara Huang, Design Haus Liberty blends mid-century and contemporary European influences across residential and commercial projects. The studio has worked with Four Seasons, Cartier, and LVMH alongside a significant private residential portfolio. Website: dhliberty.com

Elicyon. A luxury studio based in Kensington, led by Charu Gandhi. Elicyon works across interior design, interior architecture, and project management on some of London’s most prominent prime residential developments including One Hyde Park, with an international portfolio extending to Dubai, Monaco, and Singapore. Website: elicyon.com

Fran Hickman Design and Interiors. Fran Hickman’s studio is characterised by bold colour, pattern, and confident maximalism. Her residential work is full of personality and her commercial portfolio includes Soho House properties. A strong choice for clients who want distinctive, colour-forward interiors. Website: franhickman.com

Kelly Hoppen Interiors. A global name in luxury interior design, Kelly Hoppen’s studio is known for its East-meets-West aesthetic — neutral palettes, geometric precision, and harmonious spatial composition. The studio has worked on celebrity homes, luxury yachts, hotels, and aircraft. Website: kellyhoppeninteriors.com

Katharine Pooley. Katharine Pooley’s Knightsbridge studio produces polished, sophisticated interiors for the most discerning clients. Her work spans Mayfair and Belgravia townhouses through to international luxury residences and is consistently among the most refined in the London luxury market. Website: katharinepooley.com

Lawson Robb. Lawson Robb bridges architecture and interior design with particular expertise in high-end residential and superyacht interiors. The studio’s technical capability — integrating complex AV, lighting, and environmental systems seamlessly into the interior — sets it apart from purely decorative practices. Website: lawsonrobb.com

Martin Brudnizki Design Studio. Founded in 2000, MBDS is known for bold, timeless, and immersive spaces across hospitality, retail, and residential. Notable projects include Annabel’s, Bacchanalia, and numerous hotel and restaurant interiors in London and New York. Website: mbds.com

Natalia Miyar. Cuban-American designer Natalia Miyar brings an international perspective to London’s design scene. Her interiors are glamorous, refined, and impeccably detailed, with a particular strength in luxury residential. Her studio has grown rapidly since its founding and is among the most watched in the current London market. Website: nataliamiyar.com

Nicky Haslam Design. Nicky Haslam is one of Britain’s most celebrated decorators, internationally renowned for original, glamorous, and authoritatively realised commissions spanning decades. His studio continues to work across residential, hospitality, and commercial projects. Website: nickyhaslamstudio.com

Nina Campbell. Nina Campbell established her practice and shop in 1974 and remains one of the most respected and influential interior designers in the world. Known for stylish, characterful interiors and for her own collections of fabrics and wallpapers, her studio continues to deliver residential and commercial commissions of the highest quality. Website: ninacampbell.com

Oliver Burns. Led by Sharon Lillywhite, Oliver Burns Studio has become an esteemed practice serving some of the world’s wealthiest families and luxury property developers. The studio’s focus on thoughtful luxury, artisanal sourcing, and narrative-led design has produced a client list spanning Belgravia townhouses to international country estates. Website: oliverburns.com

Retrouvius. Not a conventional design studio — Retrouvius specialises in architectural salvage and designing interiors around reclaimed materials. The results are entirely unique: spaces with genuine material history and character that cannot be replicated with new materials. A first choice for clients who want sustainability and authenticity above all. Website: retrouvius.com

Rose Uniacke. Working from her Pimlico Road showroom — part gallery, part antique shop, part design studio — Rose Uniacke creates interiors of extraordinary calm and refinement. Spare, elegant rooms furnished with carefully sourced antiques and her own furniture line. Among the most admired British designers of her generation. Website: roseuniacke.com

Sibyl Colefax and John Fowler. The most venerable name in English decoration, with a client list spanning generations of aristocratic and distinguished families. The current team maintains the firm’s tradition of scholarly, comfortable English country house style while remaining fully contemporary in its approach. Website: sibylcolefax.com

Staffan Tollgård Design Group. An award-winning architectural interior design practice offering a bold take on residential interiors. Staffan Tollgård’s style draws on Asian and Scandinavian functionalism combined with a strong appreciation of furniture as sculptural art. Website: tollgard.com

Studio Ashby. Sophie Ashby’s studio is one of the most consistently exciting in London — warm, layered interiors that mix mid-century pieces with contemporary art and artisan-made objects. Recent projects include The Whiteley development in Bayswater and a growing hospitality portfolio. Website: studioashby.com

Studio Hessian. Scarlett Hessian trained as an architect and brings a rigorous spatial intelligence to residential and commercial interiors. The studio has a significant international presence across London, Stockholm, and the west coast of the United States. Website: studiohessian.com

Taylor Howes. Taylor Howes Designs operates across prime central London and international markets, delivering sophisticated, elegantly layered interiors for high-net-worth residential clients with an established presence in Mayfair, Knightsbridge, and Chelsea. Website: taylorhowes.co.uk

National Coverage

Ben Pentreath. Based in Dorset with a London office, Ben Pentreath is among the most respected English decorators working today. His interiors draw on a deep knowledge of English architectural history and decorating tradition — layered, colourful, and deeply comfortable. His influence on a generation of younger British designers is significant. Website: benpentreath.com

Eadie and Crole. Founded in 2019 by Sophie Eade and Fi Crole, Eadie and Crole operates from Hampshire with a portfolio spanning London townhouses and country house projects across the south of England. Known for elegant, understated interiors that pair subtle hues and natural textures with antiques and contemporary art. Website: eadieandcrole.com

Emily Smoor Interiors. Based in Edinburgh, Emily Smoor’s practice began as an upholstery studio and evolved into full residential and commercial interior design. Her interiors are eclectic, texture-rich, and characterised by a talent for sourcing and combining pieces from different eras and places. Website: fantoush.com

Henry Prideaux Interior Design. Henry Prideaux offers sophisticated, practical schemes notable for unexpected and extraordinary moments. Based from a showroom-studio in Twickenham with a portfolio of residential projects across London and the home counties. Website: henryprideaux.com

Max Rollitt. Max Rollitt is an interior designer, furniture-maker, and antiques dealer working from his Hampshire showroom at Yavington Barn. His interiors are distinctive for their layers of colour, texture, and history — richly composed rooms drawing on antiques, bespoke furniture, and a sophisticated understanding of English decoration. Website: maxrollitt.com

Rita Konig. British-born Rita Konig is a sought-after talent on both sides of the Atlantic, known for her acute understanding of comfortable, personal, and quietly stylish interiors. Her recent collections with Schumacher have further established her international profile. Website: ritakonig.com

SHH Architecture and Interiors. SHH is a London-headquartered practice with a national reach, known for bold palettes, architectural confidence, and exacting detail across residential, hospitality, and commercial projects. Listed in Country and Town House’s 50 Best Interior Designers in the UK in 2025 and 2026. Website: shh.co.uk

Sims Hilditch. Sims Hilditch operates from the Cotswolds and London, specialising in English country houses and town houses. The studio is known for warm, layered interiors that combine strong architectural understanding with a fine eye for antiques, textiles, and colour. Website: simshilditch.com

This list is updated periodically. If you are an interior designer or studio and would like to be considered for inclusion in a future edition, contact us via KOTHEA.com/contact.

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6 April 202628 July 2026

Pilling Resistance in Upholstery Fabric: A Guide for Interior Designers

Pilling Resistance in Upholstery Fabric: A Guide for Interior Designers

What pilling is: Small balls of tangled fibre that form on the fabric surface through friction and use, altering appearance even when the fabric remains structurally intact.
The test: ISO 12945-2 Martindale pilling test, graded 1 to 5. Grade 5 is no change. Grade 4 is slight surface fuzzing. Grade 3 is moderate pilling. Contract minimum is grade 4.
Highest pilling risk: Short-staple fibre blends, loosely twisted yarns, natural-synthetic blends.
Lowest pilling risk: Long-staple natural fibres, tightly twisted yarns, high-density weaves, mohair velvet.

A fabric can achieve 80,000 Martindale rubs and still pill badly. Abrasion resistance and pilling resistance are distinct properties measured by different tests. A fabric that resists structural wear may nevertheless develop an unsightly surface of small fibre balls within months of use, fundamentally altering its appearance without any yarn breaking. For pile fabrics in particular, pilling can destroy the visual quality of a fabric long before its structural integrity is compromised. This guide explains what causes pilling, how it is tested, which fabrics carry the highest and lowest risk, and what to specify to avoid problems in contract use.

For abrasion resistance and Martindale rub counts, see our Martindale rub test guide. For velvet types and their performance characteristics, see our velvet types compared guide.

What Causes Pilling

Pilling begins when individual fibres work free from the yarn structure through friction and mechanical stress. Loose fibre ends at the surface of the fabric are caught by adjacent surfaces and tangled together into small balls. These balls remain attached to the fabric by the fibres still anchored within the yarn, which is why they do not simply fall off. The ball continues to grow as more loose fibres are captured and incorporated into it.

The size and tenacity of pills varies by fibre type. Natural fibres produce pills that are relatively fragile and may eventually detach from the fabric surface through continued friction. Synthetic fibres produce pills that are anchored by stronger fibres that do not break under continued use. The pills grow, persist, and resist removal. This is why fabrics containing synthetic fibres often pill more visibly and permanently than pure natural-fibre fabrics.

Blended fabrics often pill worst of all. The short, weak natural fibres break loose from the yarn easily, producing the loose ends that form pill nuclei. The stronger synthetic fibres then anchor the pills to the fabric surface, preventing them from detaching. The result is persistent, anchored pills formed from natural fibre content but held in place by synthetic fibre anchors.

The Pilling Test: ISO 12945-2

Pilling resistance is tested to ISO 12945-2 using the Martindale machine with a different abradant. For pilling assessment, the fabric sample is rubbed against itself rather than against a worsted wool abradant. The machine runs for a defined number of cycles and the sample is then assessed visually against reference photographs and graded on a scale of 1 to 5.

Grade 5 indicates no change. Grade 4 indicates slight surface fuzzing or early-stage pilling, barely visible in normal viewing conditions. Grade 3 indicates moderate pilling, noticeable in normal use. Grade 2 indicates distinct pilling. Grade 1 indicates severe, dense pilling across the whole surface.

The test is typically run at 125, 500, 1000, and 2000 cycles. A fabric assessed at 2000 cycles with a grade of 4 or above is considered acceptable for contract upholstery use. The contract minimum is grade 4. A fabric achieving grade 3 at 2000 cycles will show noticeable pilling in use and is not appropriate for contract seating applications regardless of its Martindale abrasion count.

Fibre Types and Pilling Risk

Mohair. Lowest pilling risk of all natural-fibre velvets. The long-staple mohair fibre has fewer free ends per unit length of yarn than short-staple fibres. Fewer free ends means fewer pill nuclei. The smooth surface of the mohair fibre also means that free ends slide rather than tangle, reducing the rate of pill formation. Mohair velvet in contract grades typically achieves grade 4 to 5 at 2000 cycles.

Wool. Low to moderate pilling risk depending on fibre length and yarn construction. Merino wool pills less than coarser short-staple wool. Tightly spun wool yarns pill less than loosely spun yarns of the same fibre.

Cotton. Moderate pilling risk. Short-staple cotton varieties pill more than long-staple varieties such as Egyptian or Pima cotton. Cotton velvet is more susceptible to pilling than mohair velvet because cotton fibres are shorter and the pile construction exposes more free ends per unit area.

Linen. Low pilling risk. Linen is a long-staple bast fibre. The fibre length and relatively smooth surface reduce pill formation compared to cotton.

Polyester. High pilling persistence if it pills at all. Synthetic fibres anchor pills rather than allowing them to detach. When pills do form they are tenacious.

Natural-synthetic blends. Highest pilling risk in practice. Specifying blends for contract upholstery requires specific pilling grade confirmation, not just Martindale abrasion data.

Construction Factors That Affect Pilling

Yarn twist affects pilling directly. A high-twist yarn locks fibres into the yarn structure more firmly, reducing the number of free ends exposed at the surface. A low-twist yarn allows fibres to work free more easily. Two fabrics of the same fibre and weight can have very different pilling grades depending on the yarn construction.

Weave density affects pilling by controlling the movement of yarns at the fabric surface. A tight, dense weave restricts yarn movement and reduces the abrasion between adjacent yarns that generates free fibre ends.

Pile construction in velvet affects pilling through pile height and density. A short, dense pile has fewer exposed free ends per unit area than a long, open pile of the same fibre. Contract-grade velvet is typically specified with a denser, shorter pile than residential velvet partly for this reason.

Pilling in Use: What Clients Experience

Pilling in upholstery is most visible in areas of sustained friction — seat cushions where clothing rubs against the fabric, and armrests. In a hotel or restaurant environment, denim in particular is highly abrasive and accelerates pilling. Pilling is not repairable in the way that surface staining can sometimes be treated. A pilled fabric requires either mechanical depilling — a temporary intervention — or replacement. Brief clients on pilling risk at the point of specification, particularly for natural-fibre pile fabrics in contract environments.

Quick answers

What is the difference between pilling and abrasion?
Abrasion is the physical wearing away of yarn structure through friction, measured by Martindale rub count. Pilling is the formation of surface fibre balls through the tangling of loose fibre ends, measured separately by ISO 12945-2. A fabric can have a very high Martindale abrasion count and still pill badly. Both should be confirmed before specifying a fabric for contract use.

What pilling grade should I specify for contract upholstery?
Grade 4 minimum to ISO 12945-2 at 2000 cycles. For high-traffic environments, grade 4 to 5 is a more defensible specification. Always confirm the grade for the specific colourway being ordered, as pilling grades can vary between colourways in the same range.

Does mohair velvet pill?
Mohair velvet has the lowest pilling risk of any natural-fibre velvet due to the long staple length and smooth surface of the mohair fibre. Contract-grade mohair velvet typically achieves grade 4 to 5 at 2000 cycles. It is the most pill-resistant natural-fibre velvet available for contract upholstery.

Why do natural-synthetic blend fabrics pill so badly?
Natural-synthetic blends combine the pill-forming tendency of short natural fibres with the pill-anchoring strength of synthetic fibres. The result is persistent, anchored pills that grow with continued use. Blended fabrics for contract use require specific pilling grade confirmation before specifying.

For abrasion test method differences between Martindale and Wyzenbeek, see our Wyzenbeek vs Martindale guide.

For abrasion resistance, see our Martindale rub test guide. For velvet types and contract suitability, see our velvet types compared guide.

Request Samples

Order cutting samples of any fabric from our current collections. Trade accounts only.

Order Cuttings

Our Collections

Mohair Velvet Faux Leather Cashmere Throws Silks Linen Textured Upholstery

Specification Guides

Buying Guide by Purpose Crib 5 Fire Guide Martindale Rub Test BS 5867 Curtains Marine Fabric