If you wake up with knotty, frizzy hair, your pillowcase might be the culprit....

https://technivorz.com/the-ultimate-overnight-routine-for-naturally-dry-curly-hair-wake-up-with-your-curls-intact/

If you wake up with knotty, frizzy hair, your pillowcase might be the culprit. Standard cotton creates friction that snags delicate strands overnight