Colorfastness to Washing: Colorfastness to Washing (耐皂洗色牢度)
A test that measures colour change of a zipper and staining of adjacent fabric after washing with detergent. Samples are sewn with multifibre strip, washed under specified temperature and time, then rated with grey scales. Poor fastness causes visible fading and contamination in the wash, which is a common customer complaint. Dye selection, rinsing and fixation control the result, and performance levels are agreed for each colour and product type.