Waking up with knotty hair? It’s usually friction against your pillowcase....

https://romeo-wiki.win/index.php/Why_Does_My_Scalp_Feel_Drier_When_I_Sleep_on_Cotton%3F_An_Editor%E2%80%99s_Deep_Dive

Waking up with knotty hair? It’s usually friction against your pillowcase. Cotton can be rough, so switching to silk helps minimise breakage. Another simple habit is wearing a loose, low bun or braid to keep your hair smooth and protected while you sleep.