About Silk Sleep Mask - Bridal Collection Slip pure silk sleep masks are 100% pure silk, inside and out. They're made with pure silk filler, silk internal liner, and a silk-covered elastic band. Why It’s Special the slipsilk difference Slipsilk is specially-commissioned and developed and refined over ten years to provide the ultimate combination of shine, thickness, softness, and durability. Slip uses the highest grade (6A) long fiber mulberry silk, with a thickness of 22 momme and enforce the strictest quality guidelines, including non-toxic dyes. Slipsilk has been tested by an independent third-party lab and shown to absorb significantly less face cream and create 43% less friction, on average, versus cotton pillowcases. Silk fibers are significantly less absorbent than many other fibers, so they can help keep your skin’s moisture and expensive face and hair products where they belong, on your face and hair. Slipsilk can help to reduce friction, which can reduce stretching and tugging on delicate facial skin. How To Care Hand Wash with cold water only and use pH neutral liquid detergent.