International Standard/Queen size. Pillowcase dimensions: 20 x 30 - 51cm x 76cm. We spend a third of our lives in bed. In laboratory testing, slipsilk pillowcases were shown to absorb significantly less face cream than cotton pillowcases, so they can help keep your skin s moisture and valuable face and hair products where they belong, on your face and hair. Slipsilk was also shown to create 43% less friction on average which can reduce stretching and tugging on delicate facial skin.