The document discusses the properties and dyeing process of vat dyes, which are insoluble in water but can be converted to a water-soluble form through reduction. It describes the four main steps of vat dyeing cotton fabric: reduction of the insoluble dye to its soluble form, dyeing the cotton with the soluble dye, oxidizing the dye inside the fiber, and soaping for brightness and fastness. It also covers continuous and semi-continuous vat dyeing methods.

1. DYEING OF COTTTON WITH VAT DYES R.B.CHAVAN Department of Textile Technology Indian Institute of Technology Hauz-Khas, New Delhi 110016 E-mail rbchavan@hotmail.com

4. REDUCTION OF VAT DYE

12. SEMI-CONTINUOUS METHOD

19. CONTINUOUS METHOD