This season denim is back, and this time its being touted as a trend for interiors, not just fashion. Although denim tends to be associated with the classic workwear of jeans, the colour that we take from this is indigo, a rich, deep colour somewhere between blue and violet on the spectrum. When Levi Strauss created the first pair of workwear blue jeans in 1873 it was indigo that he used to colour them, but cultures in many parts of the globe had already embraced the trend for this beautiful colour centuries earlier, often on a huge scale.
In Japan Aizome is the art of dying cloth with indigo, part of an ancient set of techniques to extract and work with the dye that you can still see being done with traditional tools all over Japan today. The indigo dye (‘Ai’ in Japanese) is first extracted from the indigo plant. The leaves of the plant are dried and fermented, making a concentrate known as ‘sukumo’. This is mixed with lye and lime before being fermented again in a dye vat. The depth of colour will depend on the length of time the sukumo is left to ferment. It is proof of the cultural importance of indigo dye in Japan that the language has specific names for the depth of colours produced, ranging from ‘aijiro’, the lightest shade closest to white, to ‘noukon’, the darkest shade possible.
Earliest evidence of the plant being cultivated comes from 4000 BCE in Peru, but there are records of indigo cultivation in Japan from as early as the 6th century. Brought via the Silk Road from India, the first uses of indigo were reserved for the clothes and possessions of the aristocracy and samurai. The color of indigo was at first known as ‘Kachi’ for the brown colour of liquid indigo dye. ‘Kachi’ is also the word for ‘win’ in Japanese and the samurai had a certain superstitious belief in the colour’s power.
It was later found that cotton held indigo dye especially well, and by the Edo period in Japan the dye was used for workwear as well as many interiors fabrics. The fact that it has natural antibacterial and insect-reppelling properties helped boost its popularity. Artists of the time, including Hokusai and Hiroshige, used indigo dye in their woodblock work. The art images traditionally associated with Japan to this day are often full of indigo hues.
In modern Japan most sukumo is produced in Tokushima Prefecture in Shikoku, known as “Awa-ai” and famous for its high-quality colour. Although indigo can now be produced with synthetic dyes, the traditional method of creating the sukumo and dying the fabric by hand is still considered a valuable craft, with patience and the human touch valued in a process which is said to never produce the exact same result twice. This short film by Japanese indigo dyeing specialists Litmus shows more of the process – and why blue hands are an occupational hazard!