BeautySpaceNK The beauty secret of celebrity hairstylists dermatologists and beauty experts. What could be better than sleeping on a SLIP silk pillowcase? Wearing a luxurious sleep mask at the same time - so your beauty sleep isn t interrupted. They can help keep your skin s moisture and valuable face and hair products where they belong. SLIP silk was also shown to create 43% less friction on average which can reduce stretching and tugging on delicate facial skin. On average compared to cotton pillowcases with a 220-360 thread count. 1 x Gold pure silk sleep mask (3.3 x 8.1 / 8.5 cm x 20.5 cm).