Vat Dye

The vat dyes are insoluble complex polycyclic molecules based on the quinone structure (ketoforms). The term vat comes from the old indigo method dyeing in a vat: indigo had to be reduced to light form. Vat dyes are made from indigo, anthraquinone and carbazole. They are successfully used on cotton, linen, rayon, wool, silk, and sometimes nylon. Vat dyes are also used in the continuous piece of dyeing process sometimes called the pigment application process. The dyeings produced in this way have high wash and light fastness.