Tie-dye is a term invented in the mid-1960s in the United States for a set of ancient resist-dyeing techniques, and for the products of these processes. The process of tie-dye typically consists of folding, twisting, pleating, or crumpling fabric or a garment and binding with string or rubber bands, followed by application of dye(s). The manipulations of the fabric prior to application of dye are called resists, as they partially or completely prevent the applied dye from coloring the fabric. More sophisticated tie-dyes involve additional steps, including an initial application of dye prior to the resist, multiple sequential dye and resist steps, and the use of other types of resists (stitching, stencils) and discharge.
Vat dyes are most important dyes for dyeing and printing on cotton and cellulosic fibres. They have excellent all round fastness, which includes‐washing, light, perspiration, chlorine and rubbing fastness. Vat dyes are insoluble in water and have to be dissolved in water by using sodium hydroxide and sodium hydrogen sulphite usually at 50 degrees for 15‐20 mins. VAT dyes are classes of dyes that are classified because of the method by which they are applied. It is dying that takes place in a bucket or tank. 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 (cotton) using a redox reaction. The vat dyes have high colour fastness, which is uncommon in other dye classes.