The grey scale serves to determine the colour fastness of textiles under test. Both versions are regularly used in textile testing:
Grey Scale for Change in Colour
The grey scale consists of nine pairs of non-glossy neutral grey coloured chips, which illustrate the perceived colour differences, and is used in the assessment of colour change occurring in fastness tests, and also essential in the grading of light fastness tests.
Grey Scale for Staining
The grey scale consists of nine pairs of non-glossy grey and white coloured chips which illustrate the perceived depth of staining, and is used to assess the amount of staining occurring on adjacent undyed fabrics during fastness tests. Their use is described in ISO 105-A03.
There is also a special, large, version for the use with carpet testing.