Persimmon "kakishibu" tannin dyeing has been practiced for over a thousand years, long before chemical dyes existed. Persimmon dyeing has the effect of strengthening the fabric and repelling water. The duck fabric, which was dyed at a factory in Shiga Prefecture that has been in business for over 70 years, changes to a darker color when exposed to the sun, and even changes color in response to heat and rain, making it a material that allows you to enjoy the rugged aging of the material, somewhat like leather. Due to the nature of the aged processing, please expect variations from product to product.