LAUSR

abstract Silk and cotton fabrics were dyed with combination of three colorants extracted from Acacia catechu (AC), Alkanna tinctoria (AT), and Curcuma Longa (CL) in nine different formulations at 80°C by exhaustion method without mordanting. Dyed samples were evaluated for color value and washing fastness. The biodegradability of dye bath effluent was assessed by measuring the pH, TDS and COD of the residual dye bath liquor. It is inferred that the final color of dyed fabrics from each formulation is governed by the dominant natural dye in the dyeing combination. K/S values inferred that the exhaustion of natural dye is higher in silk fabric than cotton fabric in all formulations. It could be concluded that in the dyeing combination, colorant that have very good affinity towards the functional groups of fibers, itself acts as mordant for other natural colorants.