Fishers Finery 19mm Mulberry Silk Queen Pillowcase, Silver Pearl Our 19mm equates to 600 Thread Count; Simply the best value of any silk pillowcase available Hypoallergenic; Dermatologist recommended for Silks natural hydrating properties Promotes skin and hair health Envelope design; Slightly offset side entry; Our proprietary design allows this pillowcase to be used as a sham or pillowcase Comfortable to sleep on both sides