I love my high thread-count sheet sets as much as the next girl, but what I don't love is how moisture absorbing the cotton pillowcases are on my hair and face. Think about it. Cotton readily absorbs moisture in just about everything it touches. Sleeping on a cotton pillowcase for seven to nine hours each night wicks away much-needed moisture from our hair and (eeek!) our face, leaving us dry and flaky.
I don't know about you, but my goal is to stay as young looking as I can. So, I keep the moisture in by sleeping on satin pillowcases. Keep the cotton for the flat and fitted sheets!