Brand new sealed Black Slipsilk™ is 100% pure mulberry silk that is specially-commissioned and made to our exacting standards, developed and refined over ten years to provide the ultimate combination of shine, thickness, softness and durability. We use the highest grade (6A) long fiber 100% pure mulberry silk, with a thickness of 22 momme and enforce the strictest quality guidelines, including non toxic dyes. Includes 1 x Queen / International Standard Pillowcase (20” x 30” | 51cm x 76cm) with invisible zipper closure | Machine washable