I am usually a medium, but in volcom, the shirt sizes run small. I bought a small and it fits perfectly. The fabric is really flowy and soft. It has a built-in bra which is a definite plus, and it's not skin-tight, it's a looser fit. The racer-back strap has elastic on the back, so it gives the shirt a little stretch.
This is the perfect shirt for summer. It's simple, comfortable and your skin can breathe in it. There's a tiny embroidered volcom logo on the back side of it, which is a really cute addition.