Ai Zome is a traditional Japanese hand-dyeing method using organic Persicaria tinctoria. “Ai” means the beautiful deep blue created by the process as well as leaves of Persicaria tinctoria. “Zome” or “Some” is dyeing in Japanese. In the 700s , Persicaria tinctoria and the process were introduced into Japan from China.
In the early 1900's, artificial indigo was introduced into Japan, and popularity of the time-consuming Ai Zome started to decline. Especially during the World Wars, the production of Japanese Indigo came to a halt due to the governmental policy to convert its fields to vegetation. With this drastic change, the industry was almost wiped out entirely. Thanks to a small group of the craftsmen in Tokushima, however, the tradition is still protected and inherited today.
The hue of blue is also controlled by the liquid that is created by fermenting Sukumo (dried Persicaria tinctoria leaves) in sake and lye. The more mature the Sukumo, the deeper the blue; though, if fermented too much, the Sukumo begins to rot . The challenge is finding the perfect balance of maturity, which can only be attained through years of practice. As you can see, Ai Zome takes much effort and time. In return, it has many positive effects on people and the Earth. For example , clothing made of Ai Zome cotton is well breathable and cool in the summer, while at the same time it keeps the body warm in winter. The chemical-free dye is very gentle on the skin and is also environmentally-friendly.