Colour fastness is one of the most common fabric approval issues in apparel sourcing. A fabric may look correct when the lab dip is approved, but still create problems after washing, rubbing, perspiration, ironing or exposure to light. Buyers should define the right test before bulk orders, especially for dark shades, skin-contact fabrics and performance garments.
Which fastness tests matter most
There is no single colour fastness test that answers every question. Washing fastness, rubbing fastness, perspiration fastness and light fastness measure different risks. The right test depends on the garment use and target market.
For underwear and sportswear, perspiration and rubbing are often important because the fabric touches skin and moves during wear. For outerwear, bags or exposed panels, light fastness may become more relevant.
- Ask which test method and grade standard will be used.
- Test dark colours separately from light colours.
- Confirm whether contrast trims or linings may stain each other.
Dark colours need more attention
Black, navy, red and other deep shades often carry higher risk. More dye, different auxiliaries and stronger finishing conditions can affect rubbing, washing and handfeel. A buyer should not assume that a passed light colour means the dark colour will also pass.
Bulk approval should compare lab dip, bulk shade, handfeel and test result together. If the final garment combines light and dark materials, migration and staining should be considered early.
| Risk | Practical buyer check |
|---|---|
| Dry rubbing | Check surface colour transfer during normal handling |
| Wet rubbing | Important for sportswear and humid markets |
| Perspiration | Important for skin-contact and active garments |
| Washing | Confirms shade stability after care cycle |
| Colour migration | Review contrast panels, trims and linings |
Before approving bulk fabric
Buyers should keep approval records clear. The approved shade, fabric construction, finishing route and test requirement should belong to the same order. If yarn, dyeing route or finishing changes, the test result should be reviewed again.
A fabric factory can support testing discussion, but the buyer should confirm the final standard required by the brand, retailer or destination market.
- Approve lab dip under standard light source.
- Keep a physical reference sample.
- Confirm testing grade before bulk dyeing.
- Retest when colour, finishing or fabric structure changes.
Related fabric sourcing path
For the next step, compare the relevant fabric categories, review application requirements on the Applications page, and send a concise specification through the fabric inquiry form.
FAQ
Is colour fastness the same for every colour?
No. Dark and bright colours often need separate testing because dye load and finishing conditions can change the result.
Which fastness test is most important for sportswear?
Rubbing, washing and perspiration fastness are usually important because the garment touches skin and moves during wear.
Can buyers approve colour only by photo?
No. Photos are not reliable for colour approval. Use lab dip, standard light source and physical sample comparison.
FABRIC TESTING HUB
Review testing terms, defect control and approval requirements
Use these resources to connect color fastness, shrinkage, pilling, defect tolerance and bulk approval decisions.