Our mulberry silk pillowcases all are crafted from 100% natural protein-rich mulberry silk fabric which will give you a very great sleeping experience. Two Closure: Envelope Closure and Zipper Closure. Two Flange: Oxford and Housewife. High quality silk pillowcases will provide many years of regular use, which save for us. Protect our hair to a certain extent, Farewell to dry and frizzy hair.