Regardless of your hair type, if your hair resembles a birds nest when you wake up it's due to one main reason...."Friction against your pillowcase or sheets!" Your case maybe causing you a ton of unnecessary hair work in the morning if it's made out of the wrong material AKA cotton.
"Most bath towels are made of cotton because of it's ability to absorb moisture. It's really good at it. While that's great when you are trying to dry off after getting out of the shower, you don't want your pillowcase sucking all the moisture and healthy oils out of your hair." - Jerra Nicole From New York's William Tricomi Salon
A Cotton Pillowcase Is Like A Reverse Conditioner For Your Hair!
.....this drying issue becomes an even bigger deal if your the type guy or gal that is prone to frizz, fly aways, have coarse hair, or wirey curls.
If the drying wasn't bad enough, cotton has a relatively high friction level when compared to silk fabric. Oh yeah, remember that part where cotton likes to absorb moisture. It doesn't discriminate. It will suck the moisture right out of your skin as well. Kiss the expensive moisturizer good buy if your face touches the pillow.
High friction means more gnarls in your hair and more sleep wrinkles.
If you want to reduce hair damaging friction, and avoid slip wrinkles, you need to try sleeping on a silk pillowcase.