Colour Fastness Testing

Colour fastness testing evaluates the resistance of dyed, printed, and finished textiles to colour change and staining under specified conditions of washing, light, rubbing, perspiration, water, dry cleaning, bleaching, and other agents encountered during garment use and care. ISO 105 series (60+ parts, maintained by ISO TC 38/SC1) and AATCC test methods (100+ colour-related methods) form the global regulatory and commercial framework — virtually every apparel and textile purchase order worldwide specifies minimum colour fastness grades in 5–15 test categories. Colour change assessment uses the Grey Scale for Colour Change (ISO 105-A02, 5-step scale 1–5 where grade 5 = no change, grade 1 = severe change) and staining assessment uses the Grey Scale for Staining (ISO 105-A03, 5-step scale 1–5 where grade 5 = no staining). Instrumental colorimetry (Datacolor 600, X-Rite Ci7800, illuminant D65/10° observer, CIE L*a*b* ΔE* calculation) increasingly replaces visual grey scale grading for objectivity — ΔE*00 (CIEDE2000 formula) to grey scale correlation: ΔE*00 < 0.8 = grade 5, 0.8–1.7 = grade 4-5, 1.7–3.4 = grade 4, 3.4–4.9 = grade 3-4, 4.9–6.8 = grade 3, 6.8–9.6 = grade 2-3. Global colour fastness testing volume: 200+ million individual tests per year across accredited and in-house laboratories, driven by fast fashion seasonal testing cycles (50,000–200,000 tests per major brand per season) and regulatory compliance requirements (REACH, OEKO-TEX, bluesign, GRS).