Botanical Name

Indigofera Tinctoria

Common Name

Indigo Blue

Part Used

Leaves

Chemical Formula

C₁₆H₁₀N₂O₂

Type of Dye

Vat Dye

C.I. Number

C.I. Vat Blue 1

Main Coloring

Indigotin (Strength = 30-45%) (Swiss Method)

Component

Photospectrometer Method

Appearance

Blue

Solubility in water

4.0 to 2.0%

Heavy Metal Component

In mg/kg: Cr = 9.33, Ni=3.43, Cu=18.01, Absent = Pb, As, Hg, Cd, Co, Sb

Moisture Content

3.36%

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