Colour Fastness and Crocking: A Specifier’s Guide for Interior Designers

Crocking grade minimum for contract upholstery: Grade 4 dry / Grade 3 wet (ISO 105-X12 grey scale)
Light fastness minimum for contract interiors: ISO 105-B02 grade 5 — grade 6 for south-facing or high-light environments
Highest crocking risk: Dark colourways, velvet pile fabrics, deeply saturated reds and navies
Reverse crocking risk: New denim, dark throw cushions, and clothing transferring dye onto light upholstery

Colour fastness describes how well a fabric retains its colour when exposed to the agents most likely to cause change: light, rubbing, cleaning, and moisture. Crocking is a specific type of colour fastness failure in which excess dye transfers from one surface to another through friction. Both are routine specification criteria for contract fabric but are consistently underspecified in residential projects, which is where most complaints about colour change and dye transfer originate.

This guide explains the two tests that matter most — ISO 105-B02 for light fastness and ISO 105-X12 for crocking — how to read the grades, which fabrics and colourways carry the highest risk, and what to specify to avoid problems in use. For colour naming, systems, and metamerism — why the same colour looks different in different light — see our colour naming and specification guide. For light fastness guidance specific to room orientation and project environment, see our complete guide to light fastness and the Blue Wool Scale. For dye types and their interaction with FR treatment, see our post on dye types and FR treatment compatibility.

The Two Tests That Matter

Colour fastness is not a single test. It is a family of tests under the ISO 105 series, each measuring resistance to a specific agent. For interior fabric specification, two tests are routinely relevant and should appear on every contract fabric data sheet.

ISO 105-B02: Colour fastness to light. This test measures how resistant a fabric’s colour is to degradation by light. A xenon arc lamp simulates sunlight and the fabric is exposed for a controlled duration. The result is graded against the Blue Wool Scale from 1 to 8, where grade 1 indicates very poor light fastness and grade 8 indicates the highest possible resistance. For a full explanation of this test and the Blue Wool Scale, see our light fastness guide.

ISO 105-X12: Colour fastness to rubbing (crocking). This test measures how much dye transfers from a fabric onto other surfaces through friction. The fabric is rubbed with a standardised white cloth using a crockmeter — a machine that applies controlled pressure and movement — under both dry and wet conditions. The degree of staining on the white cloth is assessed using the grey scale for staining, graded from 1 to 5. Grade 5 indicates no staining. Grade 1 indicates severe staining. Most contract specifications require a minimum of grade 4 for dry rubbing and grade 3 for wet rubbing.

Understanding Crocking

Crocking occurs when dye that has not fully bonded to the fabric fibre transfers onto another surface through friction. Every dyed fabric contains some proportion of unfixed dye after manufacture. The degree of crocking depends on the dye class used, the dyeing process, the fibre type, and whether the fabric has been adequately washed and finished after dyeing to remove surplus dye.

Dry crocking is caused by mechanical abrasion alone. A fabric in good condition and correctly dyed will typically achieve a better dry crocking grade than wet. Wet crocking occurs when moisture is present — from perspiration, cleaning, or humidity — and is almost always worse than dry crocking because water molecules help loosen dye and carry it to the adjacent surface. This is why a fabric that appears stable in dry conditions can transfer colour noticeably on a humid day or after light spillage.

The fabrics most susceptible to crocking are those with rough or open pile surfaces, dark saturated colourways, and fibres that are difficult to dye with strong molecular bonds. Velvet is the most relevant category for interior designers. The pile surface of velvet creates more friction points than a flat-woven fabric and dye at the pile tips is more exposed to contact than dye within the body of a woven yarn. Dark velvet colourways — deep navy, rich red, dark green, charcoal — are dyed with higher concentrations of pigment and carry greater crocking risk than pale or mid-tone colourways of the same fabric.

Denim is the most commonly cited source of reverse crocking onto upholstery. New denim is typically dyed with indigo, which physically lodges within the fibre structure rather than forming a covalent bond. Indigo is easily dislodged by friction and moisture and will transfer readily onto light-coloured upholstery, particularly in warm or humid conditions. In a hotel or hospitality environment this is commercially significant: a guest in new jeans sitting on a pale upholstered chair can leave a visible mark within a single visit.

Crocking Grades: What They Mean in Practice

Grade 5: No staining. No dye transfers to the rubbing cloth. Rarely achieved by dark saturated colourways on pile fabrics.

Grade 4: Slight staining. A small amount of dye transfers but is barely visible. The minimum acceptable grade for dry crocking in most contract specifications.

Grade 3: Moderate staining. Visible dye transfer that would be noticeable in use. The minimum acceptable grade for wet crocking in most contract specifications. Grade 3 dry would indicate elevated crocking risk and should prompt discussion with the supplier before specifying for high-contact applications.

Grade 2: Significant staining. Noticeable colour transfer likely in use. Not acceptable for contract upholstery. May be flagged as acceptable for cushion or decorative applications only.

Grade 1: Severe staining. The fabric will visibly transfer colour in normal use. Not acceptable for any upholstery application.

The accepted industry minimum for contract upholstery fabrics is grade 4 dry and grade 3 wet. For hotel and hospitality environments where guests wear a wide range of clothing and the fabric is cleaned frequently, specifying grade 4 for both dry and wet provides better protection. Always confirm both grades — dry and wet — before specifying, as some suppliers report only the dry grade.

Crocking and Velvet: Specific Considerations

Velvet requires particular attention in crocking specification for two reasons. First, the pile structure creates more contact surface than a flat-woven fabric, increasing the potential for dye transfer in use. Second, velvet in dark colourways is dyed with higher pigment concentrations to achieve the depth of colour that makes dark velvet visually distinctive. The combination of pile structure and high pigment load means that dark velvets consistently achieve lower crocking grades than the same fabric in pale colourways.

This does not mean dark velvet cannot be specified for contract use. Mohair velvet in particular achieves good colour fastness due to the natural receptivity of the mohair fibre to acid dyes and the strong molecular bonds those dyes form with protein fibres. A well-dyed dark mohair velvet will typically achieve grade 3 to 4 dry and grade 3 wet, which is within the acceptable range for contract use. The key is confirming the actual grade for the specific colourway before specifying, not assuming a single grade applies across all colourways in the range.

Pale colourways of any velvet carry the reverse crocking risk: dye transfer from clothing onto the fabric. This is most acute with white, cream, and very pale colourways in environments where guests may be wearing freshly laundered dark clothing or new denim. For hotel seating in these colourways, confirm the crocking grade of the fabric in the context of incoming dye transfer, not just outgoing.

For a full comparison of velvet fibre types and their relevant specification data, see our velvet types compared guide.

Light Fastness and Crocking: How They Relate

Light fastness and crocking are distinct tests measuring different forms of colour stability, but they are both dye-related and a fabric that performs poorly on one will often perform poorly on both if the underlying dye chemistry is weak. A fabric dyed with reactive dyes, for example, will typically show moderate light fastness and may show crocking susceptibility, particularly after FR treatment. A fabric dyed with vat dyes — the most stable dye class — will achieve excellent light fastness and low crocking risk. Understanding the dye type used is therefore useful context when evaluating both grades.

The practical relationship for specifiers is as follows. A fabric that achieves light fastness grade 6 and crocking grade 4 dry is a well-dyed fabric with strong molecular dye-fibre bonds throughout. A fabric that achieves light fastness grade 3 and crocking grade 2 dry has weak dye-fibre bonds and is likely to show visible colour change and dye transfer in use within months. Neither extreme is always obvious from looking at the fabric in a showroom.

Always request both grades from the supplier before specifying for contract use. A supplier who cannot provide both grades — either because the fabric has not been tested or because the grades are not published — is a supplier whose fabric should not be specified for contract without independent testing.

Colour Fastness After FR Treatment

FR treatment can affect colour fastness. Back-coating, the most common method of applying Crib 5 treatment to upholstery fabrics, involves applying a chemical compound to the reverse of the fabric. Provided the treatment is applied correctly and does not penetrate the face of the fabric, it typically has no effect on the colour fastness or crocking grade of the face fabric.

Wet padding, used for certain curtain and lighter-weight fabrics, applies FR chemicals to the fabric in solution. Reactive dyes are known to be sensitive to the mild acidic conditions involved in some FR padding treatments. In some cases, fading can develop in the months following treatment — not immediately after, but progressively as atmospheric pollutants interact with the treated fabric. This is not visible at the time of installation and cannot be detected by standard pre-treatment testing. If specifying a fabric with reactive dyes for FR treatment, confirm with the treatment provider whether fading has been observed with that dye class on similar fabrics, and request sample swatches treated and stored for three to six months before committing to a full order.

For full detail on dye types and FR treatment interactions, see our post on dye types and FR treatment compatibility.

What to Check Before Specifying

Request the ISO 105-X12 crocking grade for both dry and wet conditions, and for the specific colourway you are ordering. Crocking grades can vary significantly between colourways within the same range, particularly between dark and pale colourways. A grade reported for the standard or mid-tone colourway in a range may not reflect the performance of the darkest available colourway.

Request the ISO 105-B02 light fastness grade for the specific colourway. As with crocking, light fastness varies between colourways and a dark colourway may achieve a higher grade than a pale one in the same range.

If the fabric is to be FR treated, confirm the dye class and whether fading problems have been observed with similar fabrics and treatments. Ask the treatment provider directly, not just the fabric supplier.

For hotel and hospitality projects, consider the reverse crocking risk for pale upholstery. The fabric’s own crocking grade tells you how much dye will transfer out. It does not tell you how resistant the fabric surface is to incoming dye transfer from guests’ clothing. Pale, tight-woven, or coated fabrics are more resistant to incoming dye transfer than pale velvet or pale linen.

Frequently Asked Questions

What is crocking in upholstery fabric?

Crocking is the transfer of excess dye from a fabric onto another surface through friction. It occurs when dye has not fully bonded to the fibre during dyeing, leaving surplus pigment on or near the surface that is dislodged by contact. Crocking can be dry, caused by mechanical friction alone, or wet, where moisture helps carry the dye to the adjacent surface. Wet crocking is almost always worse than dry. It is tested to ISO 105-X12 and graded 1 to 5, with grade 5 meaning no transfer and grade 1 meaning severe transfer. The minimum acceptable grades for contract upholstery are grade 4 dry and grade 3 wet.

Which fabrics crock the most?

Dark saturated colourways of pile fabrics — particularly velvet — carry the highest crocking risk. The pile surface creates more friction points than a flat-woven fabric and dark colourways are dyed with higher pigment concentrations. Denim is the most commonly cited source of reverse crocking onto upholstery, particularly onto pale fabrics. New denim dyed with indigo can transfer blue dye onto light-coloured seating on first contact. Cotton velvet in dark colourways has higher crocking risk than mohair velvet in comparable colourways due to the stronger molecular bond formed between acid dyes and protein fibres.

What crocking grade should I specify for hotel upholstery?

For hotel and hospitality upholstery, specify a minimum of grade 4 dry and grade 3 wet to ISO 105-X12. For pale upholstery in environments where guests wear a wide range of clothing, consider the reverse crocking risk from incoming dye transfer and prefer fabrics with tighter weave structures or protective finishes. For dark velvet in high-contact seating, confirm the specific colourway crocking grade with the supplier before ordering, as grades can vary significantly between the darkest and lightest colourways in the same range.

Does FR treatment affect crocking and colour fastness?

Back-coating, the most common method for upholstery, typically does not affect the face colour of the fabric if applied correctly. Wet padding treatments used for curtains and lighter fabrics can affect fabrics dyed with reactive dyes. Reactive dyes are sensitive to mild acidic conditions and can fade progressively in the months following treatment, a problem that is not visible at installation. If specifying a fabric with reactive dyes for FR treatment, confirm with the treatment provider whether this has been observed with similar fabrics.

What is the difference between crocking and light fastness?

Crocking is the transfer of dye to other surfaces through friction, tested to ISO 105-X12. Light fastness is the resistance of a fabric’s colour to degradation by light exposure, tested to ISO 105-B02 and graded on the Blue Wool Scale from 1 to 8. Both reflect the quality of the dye-fibre bond, and a fabric with weak dye chemistry will often perform poorly on both. They are separate tests and a fabric must be tested to both standards to report both grades. A high Martindale rub count does not imply good crocking or light fastness — these are entirely separate properties.

Can new jeans stain my upholstery?

Yes. New denim is typically dyed with indigo, which physically lodges within the cotton fibre rather than forming a chemical bond. Indigo transfers readily onto adjacent surfaces through friction, particularly in warm or humid conditions. The risk is highest with pale upholstery fabrics, particularly those with open or pile surfaces. Tight-woven, solution-dyed, or coated fabrics are more resistant to incoming dye transfer than velvet or linen. In hotel environments with pale seating, this is a practical specification consideration rather than a theoretical one.

For specification data on individual Kothea ranges see the mohair velvet, upholstery linen, and faux leather product pages.