Colour variation in the dyeing of denim yarn with indigo

In this paper, various parameters of warp yam dyeing using indigo dyes are investigated. These parameters include dye concentration, number of dips in the dyeing process, dyebath pH, amount of reducing agent, immersion time, oxidation (skying) temperature, effects of a wetting agent and soaping temp erature. This study revealed that these parameters have varying degrees of influence on the resultant colour of the samples dyed. The degrees of Varia tion in colour were expressed using the CIE L*a*b* system as well as the sh ade depth (Integ).