Colourfastness

Definition

A fabric's resistance to colour change or colour transfer when exposed to washing, light, perspiration, rubbing, or other environmental factors. Colourfastness is measured on a 1-5 grey scale, where 5 indicates no colour change. Testing standards include ISO 105 (washing), ISO 105-B02 (light), and ISO 105-X12 (rubbing). Dark colours and reactive dyes require particularly rigorous testing to ensure they do not bleed or fade prematurely.