VAT Dyes

The VAT dyes once obtained only from plants but now often produced synthetically. Although almost all dyeing can be done in a vat, the term vat dye is used to describe a chemical class of dyes that are applied to cellulosic fibre (i.e., cotton) using a redox reaction. The chromophore renders water insolubility. From an aqueous media, dyes are reduced and solubilized. In this state dyes show affinity for fibers. After dyeing with the leuco compound, oxidation process is carried out to get back the insoluble pigment form. VAT dyes are made for industrial purposes.