NBN EN 20105-A02:1995

Describes the grey scale for determining changes in colour of textiles in colour fastness tests, and its use. A precise colorimetric specification of the scale is given as a permanent record against which newly prepared working standards and standards that may have changed can be compared. The essential scale (5 steps) consists of pairs of non-glossy grey colour chips (or swatches of grey cloth). In addition, an augmented scale includes four half-steps and, thus, 9 steps.