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

https://fair-wiki.win/index.php/Why_Are_Australian_Women_Talking_About_Overnight_Hair_Protection_Lately%3F

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