BeautySpaceNK Slip Pure Silk 360 Thread Count Charcoal Silk Pillow Case King The beauty secret of celebrity hairstylists dermatologists and beauty experts. THE SlipSILK DIFFERENCE: Slip pure silk products are made using slipsilk developed and refined for over ten years to provide the ultimate combination of shine thickness softness and durability. ANTI AGING: We spend a third of our lives in bed. In laboratory testing slipsilk pillowcases were shown to absorb significantly less face cream than cotton pillowcases so they can help keep your skin s moisture and valuable face and hair products where they belong on your face and hair.