Love it so I bought a set of six (6). This Nurse likes pillow covers to protect our pillows and I highly recommend them because:
Cotton - you get less sweaty and it absorbs sweat. 
Zipper - easy on and off for washing
Launders well. Can use hot water. 
Protects pillows from smelly hair oil and some stains. 
Great price. 
I buy a lot of these and if/when they get smelling like hair oil, I replace them because they are inexpensive. 
However, they only sell the standard pillow size so it might not fit Queen size pillows, and they don't have King size.