from the makers of the award winning slip™ 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. n laboratory testing, slipsilk™ was shown to absorb significantly less face cream and create 43% less friction, on average, compared to widely-available cotton pillowcases with a 220-360 thread count.