Regular Waist, Cotton, Slit Detail, Denim Trousers - Slim Jean | Koton Slim Jean, which accompanies all little free spirits with pleasure, is appreciated with its slit detail. Indigo Product Usage Information: The indigo dye used in our product may give some color to your clothes during use. We recommend that you wash it inside out and alone for the first wash, and in the next washes, on the reverse side and together with colored clothes.