I bought this pillowcase to prevent wrinkles/sleep lines.As many other reviewers have noticed, the description is a little misleading. It's not silk and while you can call it "silky," it is still just shiny polyester.I haven't had any issues with the pillowcase coming off. One reviewer suggested a zipper, which would be nice, but the pillowcase does have a 6" pocket that comes over the top of the pillow (see pictures) so it is not wide open. Understandably, if you are a violent sleepSee full review