Indigo Dye – The One And Only Blue Gold
Denim today can be found in many colours; women’s denim in particular is increasingly available in a broad palette. There is one shade of denim, however, that has been around for longer than them all, and is still the most common colour of denim available.
Indigo put the “blue” in blue jeans, and the dye and denim have had a long and successful career together. To give an idea of how popular Indigo is, it takes about 3-12 grams of indigo dye for a pair of jeans, and thousands of tons of Indigo dye are produced each year (most of which is actually used to make denim).
The cotton fibers used in denim were difficult to dye using other dyes, so traditionally Indigo became the primary dye used for cotton. This was the case going back to when denim was first being made in it’s namesake city Nîmes in France (the “Nime” in the cities named is believed to be the second part of the word “denim”).
The majority of Indigo used today is synthetic, made using a process that was perfected late in the 1800’s. Originally Indigo was a natural dye, harvested from a plant called Indigofera tinctoria. It was initially domesticated in India for use as a dye, and this association with India is reflected in the modern name “Indigo”. By the end of the 1800’s 7,000 square kilometers were dedicated world wide to meet demand for Indigo dyes.
Even though Indigo was more effective at dying cotton than other dyes, it still wasn’t easy to work with. Indigo itself is not soluble in water, so complicated chemical steps are necessary to get Indigo to adhere to the cotton threads used to make a cloth.
Working as an indigo dyer in pre-industrial Europe could be a dangerous profession due to the toxic chemicals involved. It could also be an unhygenic one; one of the techniques used during the dying process in pre-industrial Europe involved dissolving the Indigo in stale urine!
Most jeans today are dyed using the synthetic forms of indigo. However, some denim makers believe that the best results can still be found from the natural form. For instance, you can see Momotaro Jeans explains their use of natural indigo.
What do you think about indigo vs. other dyes when it comes to denim? Let us know in the comments!