Very stretchy fabric shows every flaw.  M was too tight, so ordered Large.  It is not even an inch bigger (it was hard to see any difference at first), so trying the XL.  (I usually wear 6 or 8 and S or M in less stretchy fabrics.)  Otherwise, it is cute!  It's Modal, which it a plant product, and is supposed to hold more water than cotton, so it dries slowly.  Probably won't use it for travel.