Colour fastness is a term—used in the dyeing of textile materials—that characterizes a material's colour's resistance to fading or running. Colour fastness is the property of dyes and it is directly proportional to the binding force between photochromic dye and the fiber.

What is meant by Colour fastness?

The colour fastness following exposure to light of a material is defined as the level of change in colour it undergoes when exposed to light (ISO 105 B02:1994). This is measured using a specimen of the fabric to be tested.

Why is Colour fastness important?

Abstract. In testing the quality of fabrics, one of the most important test is colorfastness. Colorfastness is a property of a colorant which allows it to retain its different characteristics despite coming across degrading conditions. Colorfastness tests are conducted under standard methods.