I tried out the Purity Home 400TC Percale MiG Cotton Pillowcases, KPC, Light Gray, and they wrinkle a lot.  They are wrinkled coming out of a hot dryer.  I hate ironing.  I love the idea of pure cotton, but I forgot that cotton is high maintenance.  I thought the 400 thread count would be softer; it's not.  I wasn't impressed with these pillowcases and wouldn't buy again.