This standard specifies the gray sample card and its application method for evaluating the degree of staining of adjacent fabrics in textile color fastness tests. The precise colorimetry grade value of this gray card can be used as a permanent record for comparison between the newly produced gray card and the gray card that has changed during storage or use.
GB 251-1995 history
2008GB/T 251-2008 Textiles.Tests for colour fastness.Grey scale for assessing staining