The Effect of Washing on Color Unevenness in Cotton Cloth Dyed with Natural and Synthetic Indigo

Abstract

The effects of washing on color were quantitatively examined using a colorimeter to elucidate subtle color difference between cotton cloth samples dyed with natural indigo and synthetic indigo. Color produced by reactive dye and indigo was also compared and the results were analyzed by a CIELAB color system. Color unevenness was subjectively evaluated by seven professional indigo dyers. With repeated washing, L^* value in cloth dyed with natural indigo increased at a lower rate than in cloth dyed with synthetic indigo. Color unevenness is related to dye absorption and dye aggregation.