Natural indigo dyes Atural indigo dye c.I.Vat blue 1, formula c16h10n2o2 is extracted from the leaves of the plant indigofera tinctoria. The product is entirely herbal and safe on the skin and has medical properties. It is used as dye on all types of yarn and fabrics. Indigo dye comes in the form of cakes. It can be powdered if specified. The production season for indigo dye is from august to december. The indigo leaves are used to make hair dye as well as prepare medicated hair oil. Description of natural indigo dye It is prepared from leaves of indigo plant by natural fermentation process. Botanical name Indigofera tinctoria Common name Indigo blue Part used Leaves Chemical formula C16h10n2o2 Structure Type of dye Vat dye C.I. Number C.I. Vat blue 1 Main coloring component Indigotin (strength=35-43%) (swiss method) photo spectro metre method Appearance Blue Solubility in water 4.0+2.0% Heavy metal continent Zn= 27ppm, cr=1.6ppm absent=pb, as, cu, hg, ni, cd. Moisture content 5+1.0% Ph. Of 1% solution 7+1.0 Specialty Color changes to greenish yellow in alkaline medium. Dyeing The process of dyeing cotton, wool & silk is almost same. The process is like that of vat dyes. The dye has to be dissolved in reduced state, then oxidized to get the shade blue. Colors imparted Blue. As required