If you want something to keep you warm that's not going to show bulk under your tightest sweater, this is what you want.  In fact it's so sheer, I can't even find mine.  I think it's hiding somewhere in the inner reaches of my washing machine or maybe clinging to one of my bed sheets.  Other than that, it's fine;  easy to wash and it dries (not in the dryer) in a very short time.  Now if I could just find it....