Colorfastness

Colorfastness measures how well a dyed or printed garment holds its color under stress: washing, light exposure, rubbing (called crocking), and perspiration. Testing follows standardized methods like AATCC gray scales, graded 1 through 5, where 5 means no visible change or staining and 1 means severe failure. Reactive dyes on cotton typically test in the 4 to 5 range for wash fastness; cheaper direct dyes can drop to 2 or 3 after just a handful of home washes.

Uniform buyers care about this spec more than almost anyone else in the industry — a landscaping crew ordering navy polos that get washed weekly for a full season needs color that survives dozens of cycles, not just the first one. Race-day and single-event tees get worn and washed a handful of times at most, so a supplier can get away with a lower-fastness dye there in a way a five-year uniform program can't tolerate.

Ask for the AATCC wash-fastness rating before committing colored blanks to any long-life program — workwear, team uniforms, retail stock that'll sit on a rack for months. Expect a fastness premium built into pricing on saturated colors like true red and navy, which hold dye less readily than mid-tones and pastels.

Surviving the washing machine is only one test colorfastness has to pass. Light fastness — resistance to fading from sun and UV — and crocking — color rubbing off dry onto skin or upholstery — are tested and rated separately, and a garment can pass one of these while failing another.