I'm normally a Medium in tops but I size up when purchasing bodysuits to give room in the crotch and chest/breast area, so I bought a large. It has stretch. Good material. Not thin. Super comfortable. Purchased this top in black and white. The white is slightly see-through. Barely. Just wear the right color bra and you'll be fine. I'm a 36 C. 5'6 1/2. 170 lbs. Pretty evenly proportioned with most of my weight in my lower half for size reference purposes. Hope this helps.