With the stretch panels on the end, these sheets fit perfectly on a deep mattress. I purchased these queen size as a gift for my mother after purchasing the king size for my 18" deep mattress. I've had my sheets over a year. The sheets fit perfectly on my mattress, wash well, and do not pill. They are a heavy flannel. On my king size, there was a small thin flaw in the fabric that eventually wore through. I just stitched it up. Since I have a problem finding sheets deep enough that fit well, this wasn't an issue for me. I plan on ordering another king set for myself. I would have given an excellent rating except for the fabric flaw in my sheets.