The use of reflectance measurements in the determination of fixation of reactive dyes to cotton

The utility of the Kubelka-Munk equation for determining the fixation of reactive dyes to cotton has been assessed. Large K/S values are not linearly related to dye concentration on fabric and thus give an inaccurate assessment of fixed dye. If lower values of K/S are selected, by measuring at a suitable wavelength, a linear relationship exists with the concentration of dye present, even at very heavy depths of shade. Thus, by judicious choice of wavelength, K/S values can provide an accurate and convenient method for the assessment of dye on fabric, provided that a reference fabric sample, with a known concentration of the same dye, is available as a standard for comparison. Significant implications are then revealed for construction scalable models of opaque medium reflectance that are homogeneously linear over wavelength with respect to colorant concentration change.