Cotton pillowcases create unnecessary friction, leading to frizz and breakage...

https://www.last-bookmarks.win/if-you-re-waking-up-with-tangled-frizzy-hair-it-s-usually-down-to-friction

Cotton pillowcases create unnecessary friction, leading to frizz and breakage while you sleep. Swapping to silk allows hair to glide, reducing damage. For extra protection, secure your hair in a loose braid or scrunchie