I put dust mite covers on all of my pillows and encase all of my mattresses in dust mite bags. these are some of the best. I used to purchase the cheaper as well as some non cotton dust mite covers but they would pill and tear and I would be throwing them away after a short time. These are so much nicer, lasted longer, and are much nicer. I know when I have a pillow without one of these on it because I start having allergy issues. They work great if you have a dust mite allergy...