Cotton pillowcases create friction that leads to breakage and morning frizz....

https://www.ready-bookmarks.win/waking-up-with-bedhead-friction-causes-damage-so-swap-cotton-for-silk-for

Cotton pillowcases create friction that leads to breakage and morning frizz. Swapping to silk helps, but a loose braid or silk scrunchie is just as effective. Protecting your hair overnight is a simple habit that makes styling much easier once you wake up