Fig. 4From: Statistics of the early synthetic dye industryISO lightfastness ratings in the third edition of the Colour Index [22], for colourants listed in the first edition [16]. Data selected for normal depth of shade, and direct dyeing without aftertreatment where applicable. ISO values for mordant dyes primarily relate to wool with chrome mordant. A small number of duplicates with the same CI generic name was removed for this plotBack to article page