Stop waking to a bird's nest. Constant friction from cotton causes frizz and...

https://www.female.com.au/why-more-australian-women-are-rethinking-their-night-time-hair-care-routine.htm

Stop waking to a bird's nest. Constant friction from cotton causes frizz and stubborn morning tangles. Small habits, like a silk pillowcase or a loose braid, protect your hair while you sleep. It is an easy way to keep locks smooth