Amasagi Zenmai-ori is a rare textile that incorporates the fibers of zenmai (royal fern). The soft, cotton-like fibers stripped from young fern shoots are combined with silk threads on a spinning wheel. Dried zenmai fibers are twisted into the silk along with waterfowl down, then woven into fabric. It takes about two months to complete a single bolt. Zenmai fibers are naturally resistant to insects and mold, while waterfowl down provides water repellency, making this textile highly valued.