slip Queen/Standard Pure Silk Pillowcase in Pink. slip Queen/Standard Pure Silk Pillowcase in Pink. Made from 100% highest grade (6A) long fiber mulberry silk with a thickness of 22 momme. In Desert Rose - limited edition color. Silk fibers are significantly less absorbent than many other fibers and reduces hair and skin friction. Non-toxic dyes & machine washable. Fits queen/standard size pillows (measures approx 20 H x 30 L). Pillow not included. Due to the unique wash, colors and patterns may vary slightly. Imported. SLIP-WA3. 810046980750. 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.