Discoloration from repeated machine washes and early fading in manufacturing textiles can indicate a lack of quality. Colorfastness tests have gained international significance. There are many methods that can be used to test for colorfastness and dyes. These are the most important:
Grey Scale to Assess Change in Colour: The Grey Scale can be used to assess changes in leather colour in colour fastness tests such as wash fastness and perspiration fastness. This scale is made up of nine pairs each of grey colour chips, which represent a visual contrast and difference.
Grey Scale to Assess Staining. This Grey Scale can be used to assess the staining of dyed leather during colorfastness tests. The staining of wool or cotton fabrics in wash fastness, sweat fastness, and others. Nine pairs of grey color chips make up the scale, each one representing a visual contrast and difference.
– Colour Fastness Leather to Light: This method can be used to determine the resistance of leather to light. The Xenon lamp emits light at a wavelength that is close to daylight. Under controlled conditions, the side of the leather sample to be tested is exposed to light from a Xenon lamp. Eight blue-dyed wool standards (blue range) are also used. By comparing the leather’s fading with that of the blues standards, the light fastness of the leather is determined. To aid in the evaluation, the fading is usually done within two exposures.