Kings of Indigo (K.O.I.) has been named one of the most sustainable fashion brands in the world by Rank a Brand. It is a Dutch brand that combines the best of the jean traditions of Japan and America and stands out because of the beautiful details in the products. The jeans are made of organic cotton, under good working conditions. In addition to jeans, you can find other K.O.I. items such as blouses and jumpsuits at Sophie Stone. You can read more about the background of Kings of Indigo here.