Dye that runs in the first wash is dye that was not fully fixed to the fibre or not fully washed off after dyeing. Strong reds and other deep or bright shades on cotton are the usual cases, because they need a lot of dye. A small amount of colour in the first wash water can be normal for some products, but staining other garments is a quality problem and gives customers a reason to return the item.

What the test measures

ISO 105-C06 tests colour fastness to domestic and commercial laundering. It reports colour change in the specimen and staining on attached undyed fabrics, each graded against a grey scale. The staining grade is the one that matters for bleeding. Ask for the staining result on the multifibre or adjacent fabrics, not only the colour change of the tee.

Common causes

Bleeding usually comes from insufficient washing off of unfixed dye after dyeing, from a dye or process poorly matched to the shade depth, or from a shortcut at the dye house. Garment-dyed products and heavily washed finishes can behave differently from piece-dyed fabric. Check whether the bleeding is limited to certain lots or colours, since that points to a process issue.

What to do with the stock

Send retained garments from the affected lot to a lab and wash them with a named procedure such as ISO 6330, using a white adjacent fabric. If staining is poor, ask the factory to re-wash the lot or dye house to re-process it, and re-test before shipment. Do not ship and rely on the label.

The care label

Under the FTC Care Labeling Rule, 16 CFR Part 423, a care label must warn when any part of the prescribed washing procedure would harm other items washed with the product. The rule gives the example that a shirt which is not colourfast should say “Wash with like colors” or “Wash separately.” A label is the last resort, though: for tees sold to everyday customers, good wash fastness is the better answer.

What to put in the spec

Write a minimum staining grade for washing, name the test method and wash conditions, and require a pre-production test on each dyed lot for dark and bright colours. Keep a sealed approved lot for comparison.