Indigo is the dye used in coloring blue jeans. The term navy blue is derived from the use of indigo to dye British naval uniforms in the eighteenth century. The structure of the indigo molecule is a. Oct 15, 2013 · The Problem with the Fashion Industry’s Indigo. By Emma Barker. October 15, 2013. Latest. Science. How scientists imagined and built an undersea utopia for humans. Diy. Included in the family of vat dyes is the well known natural dye indigo. While indigo is still the most important colourant for denim fabric, its a-typically small size causes this vat dye to be very susceptible to removal in a laundering process, giving jeans a faded appearance even after one wash.

Indigo is among the oldest dyes to be used for textile dyeing and printing. Many Asian countries, such as India, China, and Japan, have used indigo as a dye for centuries. India is believed to be the oldest center of indigo dyeing in the Old World. It was a primary supplier of indigo to Europe as early as the Greco-Roman era. Denim makers have three ways to dye: with 100% indigo, a with mix of indigo and sulfur, and with 100% sulfur. The latter is what’s used for black and colour denim. In the 1970s, when denim makers scaled for mass production, sulfur was introduced to replace (some of) the indigo baths to cut costs.