They are also extremely inexpensive. I got a black one last week. It's an Ikea sheet, 100% cotton. I think it was full size but it was not marked. I held it to my cutting board and rough measured it. It was about 5 yards of fabric. I paid $4 for it and I don't have to worry about it bleeding to boot. I should try to figure out how to determine if a particular sheet has an especially high thread count before I buy it. That would be helpful. Any ideas on how I could do this? Hold it up to the light maybe?