Kakishibu-zome washi tread, 1000 m (32.8 feet), made from Osawa washi, kozo
Kakishibu (persimmon astringent juice) is a natural waterproofing pigment. It is extracted after not-yet-ripe, astringent persimmons are crushed and squeezed into liquid, which is then kept in clay pots in a dark, cold area so the liquid can ferment and age for three months to one year. The cloth is exposed to sunlight for coloring after immersing it in the persimmon astringent liquid or brushing the juice over the cloth at room temperature. At the beginning, the cloth appears light beige. As it is dyed repeatedly, however, the cloth turns darker, from red brown to umber. During this period, the cloth also turns into a hard, leather-like texture. Because of its high waterproofing property, persimmon juice was always applied to fishing nets, as a base coat for japan ware, to coarse oil-paper umbrellas (bangasa in Japanese), rainwear, and stencil patterns.