slip Contour Sleep Mask in Crimson. slip Contour Sleep Mask in Crimson. The beauty secret of celebrity hairstylists, dermatologists and beauty experts. Protect your lashes with this limited edition contour sleep mask. Beauty sleep with benefits.. The slip contour sleep mask has been specifically designed with delicate eyelash extensions in mind. The shape of the contour on the inside of the sleep mask has been designed to sit away from your eyelids and allow additional space for your eyelashes to sit while you get your beauty sleep. The slip contour sleep mask is made with slipsilk, the same silk used in the award-winning slip pure silk pillowcase. 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. SLIP-WU129. 810046987483. 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.