摘要 |
A method for making a dye mixture to produce a target colour on a given substrate, comprising the steps of: -a) measuring reflectance values R<SUB>T</SUB>(lambda<SUB>i</SUB>) of the target colour at a plurality of wavelengths lambda<SUB>i</SUB>=1, 2 . . . n; b) measuring reflectance values R<SUB>s </SUB>(lambda<SUB>i</SUB>) of the substrate at the same wavelengths lambda<SUB>i</SUB>; forming a set of concentrations c<SUB>j </SUB>of M dyes in the calculated concentrations; the database having been compiled by aa) making dyeings of combinations of the dyes Dn at different concentrations; bb) measuring the reflectance values R of the dyeings at different wavelengths; cc) defining a function f(R); dd) defining a relationship between f(R) and c involving constants g and k; and ee) for each dye Dn determining constants g<SUB>n</SUB>, k<SUB>n</SUB>, such that the calculated values for f(R), c, g<SUB>n </SUB>k<SUB>n </SUB>approximate closely the measured values. |