I bought these because standard sheets won't stay on my son's bed, which has a feather bed on top of the mattress. These work perfectly, and don't pop off the corners. They are very thick cotton and soft. I followed the instructions to the letter (wash before using, use cold water and 1/2 cup white vinegar to prevent shedding/piling), which seemed to work, because we aren't having a problem. Very good product for the price. I would buy them again.