Yuki tsumugi silk is produced principally in the reaches of the Kinu River that straddles the Ibaraki and Tochigi prefectures. Although it is considered a luxury fabric today, Yuki tsumugi silk originally started as a subsidiary business of the silk production in the region. Yuki tsumugi silk kimonos are characterized by their lightness, softness, and excellent heat retaining-properties. The threads are extracted from yarn handspun from silk floss.
For more detailed information including a description, history, and the general production process, please see the Kogei Japan: Traditional Crafts of Japan website.