Study on the Compatibility of a Binary Mixture of Babul Bark and Other Natural Dyes Used on Gallnut Pre-Mordanted Cotton Fabric for Developing Compound Shades

Abstract

Cotton fabric that has been pre-mordanted with gallnut extract was dyed using a binary mixture of aqueous extracts of the natural dyes such as babul bark with bixa (annatto) seeds, Rheum emodi (rhubarb) roots and pomegranate rind extracts to obtain compound shades. The compatibility of each binary pair of natural dyes was assessed by (a) a conventional process of analysis through progressive development of shades by changing time and temperature in one set, and variation in the total concentration of dyes in the mixture in the second set with 50:50 dye proportion and (b) by a newer approach of analysing the relative compatibility rating (RCR) of each pair of dyes by varying proportion of both the dyes (75:25, 50:50, 25:75) in the mixture. The study indicates that all three pairs of binary mixtures (babul bark with annatto seeds, babul bark with pomegranate rind and babul bark with Himalayan rhubarb roots) are found to vary in their respective degree of compatibilities and are differently compatible (moderated, fair and average) as determined by the newer RCR method. Interestingly the degree of compatibility found by the conventional method nearly matches with the newer method showing the efficacy of the RCR method/technique.