Colorfastness is the resistance of a textile's color to change or to transfer when the textile meets conditions it will see in use: washing, rubbing, light, sweat, water, chlorine, dry cleaning and so on. A fabric with poor colorfastness fades, changes shade, or stains other garments, the wash load, a car seat or the wearer's skin.
Buyers set colorfastness requirements for almost every textile product. The tests are standardised so that results from different laboratories can be compared.
Two things are measured#
Every colorfastness test looks at two separate effects:
- Color change: how much the tested fabric itself changes in color.
- Staining: how much color moves onto adjacent undyed fabrics, called adjacent fabrics or multifibre strips.
A fabric can have excellent color change and poor staining (it holds its shade but bleeds a little dye onto white fabric), or the other way round. Reports give separate ratings for each.
Grey scales and ratings#
Results are judged visually against standard grey scales under controlled lighting:
- The grey scale for color change compares the tested and original fabric.
- The grey scale for staining compares the stained and unstained adjacent fabric.
Ratings run from 5 (no change or no staining) to 1 (severe change or heavy staining), with half grades such as 3-4 in between. Higher is better.
| Rating | Meaning |
|---|---|
| 5 | No visible change or staining |
| 4 | Slight |
| 3 | Noticeable |
| 2 | Considerable |
| 1 | Severe |
Instrumental color measurement can also be used where a method allows it, but many specifications still work in grey scale grades.
The main tests#
| Test | What it simulates | Typical concern |
|---|---|---|
| Washing | Home laundering | Fading, dye bleeding onto other garments |
| Rubbing (crocking) | Friction in wear, dry and wet | Color transfer to other surfaces |
| Perspiration | Contact with sweat | Staining of skin and linings, shade change |
| Water | Contact with water or rain | Staining when wet |
| Light | Exposure to daylight | Fading on shoulders and exposed areas |
| Chlorinated water | Swimming pools | Fading of swimwear |
| Saliva | Mouthing by babies | Required for some babywear |
The main method families are the ISO 105 series and AATCC test methods. Each buyer names the exact methods and required grades in its manual. See ISO, ASTM and AATCC test methods for how these families differ.
Reading a colorfastness report#
A typical report line looks like this:
| Test | Color change | Staining (wool / acrylic / polyester / nylon / cotton / acetate) |
|---|---|---|
| Washing | 4-5 | 4 / 4-5 / 4-5 / 4 / 3-4 / 4-5 |
Here the fabric holds its own color well, but stains cotton slightly more (3-4). If the buyer requires 4 on all staining, this fabric fails on cotton staining.
Check three things on every report:
- Method and conditions: the exact method, temperature and procedure the buyer asked for.
- Which rating failed: change or staining, and on which fiber.
- Fabric state: whether the tested sample is the bulk shade and finish.
Why fabrics fail#
- Unfixed dye left on the fiber after dyeing because of poor washing off (soaping).
- Wrong dye class or recipe for the fiber and the end use.
- Deep shades, which carry more dye and are harder to clear.
- Finishes such as some softeners and resins that affect fastness to rubbing or light.
- Pigment prints with insufficient binder or curing, which rub off.
What to do when a fabric fails#
- Confirm the test was done to the correct method and on the correct fabric.
- Ask the dyehouse about wash-off, fixing agents and recipe. Additional wash-off or an after-treatment often improves wet fastness.
- Review the finish: softener type and amount affect rubbing fastness.
- Re-test a corrected sample before bulk shipment.
- For garments, consider care label wording carefully, but do not use care labels to hide a fastness problem that the buyer's standard does not allow.
Related guides#
- Colorfastness to rubbing
- Colorfastness to washing
- Colorfastness to perspiration
- Defects: color bleeding and poor rubbing fastness
- Fabric testing standards and methods: color fastness within the full test program.
- Pantone color guide and its application in textile: approving the shade before fastness testing.