Tossing and turning creates friction that causes hair breakage. While silk...

https://bizzmarkblog.com/do-i-need-silk-to-reduce-frizz-or-can-i-just-change-my-habits/

Tossing and turning creates friction that causes hair breakage. While silk pillowcases help reduce this, the best habit is securing hair in a loose plait or bun before bed. It’s a simple way to protect your ends and wake up with fewer tangles.