This is Silk
The blurb on the box tells you everything you need to know about this little piece of luxury, which announces itself as an eight-hour beauty treatment, which will give you anti-ageing, anti bedhead hair and anti-sleep-crease benefits while you sleep. Where cotton and synthetic fibres in pillowcases can create friction, which drags skin and hair, these pillowcases are made from a superior grade of mulberry silk which is soft and smooth. The founder of the company, Sonal Keay, spent a long time sourcing the quality of silk.
She settled for a 22 momme weight because she finds the thicker silk smoother and more lustrous and, crucially, it emerges perfectly from a delicates machine wash (at max 30C). She felt that it important that, if looked after well, her pillowcases would last a long time, and they are supremely washable, with the slightly thicker and heavier pure white silk feeling gorgeous on the skin, very soft and with no seaming, except at the sides.