slip Sleep Mask in Beauty: NA. The beauty secret of celebrity hairstylists, dermatologists and beauty experts. What could be better than sleeping on a slipsilk pillowcase? Wearing a luxurious slipsilk sleep mask at the same time (so your beauty sleep isn't interrupted). Includes 1 x yacht club pure silk sleep mask with piping. 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. A sleep mask made with slipsilk and designed for 8 hours of uninterrupted beauty sleep. Measures approx 8.1 W x 3.3 H. SLIP-WU105. 810046986363. In 2003, slip Co-Founder and CEO Fiona Stewart was prescribed acne medication which resulted in extremely sensitive skin and thinning hair. Her dermatologist suggested sleeping on a silk pillowcase. Unable to find one, she sourced the best silk she could find and wrapped it around her pillow. The results were dramatic and immediate, she's never looked back. She had stumbled upon a long-forgotten beauty secret - and slip was born.