Indigo is often referred to as a “living colour,” and the fact that indigo dyed jeans fade over time is the single most unique feature that differentiates denim from all other fabrics. But what is the reason for this – why do we continue to make and wear garments that purposely lose their colour?
The technical reason for indigo dyed denim’s ability to fade is fairly simple. Unlike most other dyestuffs, the indigo dye doesn’t penetrate to the core of the yarn. When the denim is worn and gets abraded, the indigo slowly rubs off and the white core gradually becomes visible.
For thousands of years, natural indigo was extracted from plants. The dyestuff is expensive to produce and the dyeing process is difficult to control. In 1897, a synthesised and much less costly version of indigo dyestuff was put into production. But the formula for synthesised indigo wasn’t conceived overnight. Its origins trace back to 1865 when the German chemist and Nobel Prize winner, Adolf von Baeyer, began working on the formula. According to Wikipedia, 17,000 tons of synthetic indigo were produced worldwide in 2002. To put that into perspective, one pair of blue jeans requires 3–12 grammes of indigo to become blue.
Our designers are inspired by the natural fading process that raw denim undergoes when it’s worn, which can take months or even years. The wear results that patient raw jeans wearers achieve are reproduced through prewashing and treatments. In most cases, jeans are sewn from unwashed and untreated denim. Before trims and labels are added, the jeans undergo different processes to get specific looks.
In addition to different weaving techniques and the almost infinite ways of treating denim, the way that the yarn is dyed is the most important factor for how the jeans will eventually look. The dyeing process is also one of the aspects of jeans production that has seen most innovation during the past years.
The famous Italian denim mill Candiani has developed a way to reduce water consumption when dyeing denim. The method delays the oxidation process and lets indigo penetrate the yarn a lot faster. This in turn reduces water consumption and the amount of by-products, making the technique eco-friendly and sustainable. Learn more about our sustainable jeans production initiative Low Impact Denim here.