I have natural curly hair..which needs more moisture over straight hair..I have used 'lingerie-satin' type..both materials work the same...and the pillow becomes 'slippery' if using 2..slips out of place..
I learned about these pillow cases from a radio show I heard while driving. I had long been frustrated by silk or satin pillowcases that were expected to prevent bed head and did not. These met my satisfaction. They are extraordinarily soft. I love the grey color. And most mornings, I can jump out of bed with little to no hair care and head out the door for coffee.