Very stretchy and extremely comfortable!! Nice heavy, thick knit with lots of air flow. There is not an under-layer but you can easily layer over a slip dress and be fine! If you don’t wear a slip under. The knit around your hips and chest/bust is tight knit and not see through. The upper chest, torso and legs portions have a looser knit where skin is slightly visible under. Get so many compliments on this one!! XXS but extremely stretchy so can fit up to a med with a more body con look!