I don't know why I didn't just go to a brick-and-mortar and buy sheets that I could feel and see what I was purchasing. These are NOT cotton, unless they fall under the category of "cotton" that is made from plastic.  There is no way they have a thread count of 600.  These are going right back, I better get my money back. I would categorize this as false advertising. I would give negative stars if I could.