Japanese Indigo

(Chinese indigo; Dyers knotweed) Source of a blue dye used in East Asia since ancient times. On the Japanese island of Shikoku the art of indigo dyeing, known as aizome, is still practiced following traditional methods that go back centuries. Clothes made with aizome fabrics are remarkably cool in summer and warm in winter. The dye is also antimicrobial and anti-inflammatory, which is probably why the samurai wore aizome clothing under their armour to help prevent rashes caused by chafing and perspiration. A blue powder called chung-dae made from the herb has been used for centuries to treat infectious inflammatory diseases, ulcerative colitis, and fever. Recent studies have confirmed its potent anti-inflammatory properties and its effects on chronic gastrointestinal disease and on atopic dermatitis, a common form of eczema. Easy to grow annual. Here is a video on how to extract the dye.