The cotton fabric is soft, lightweight enough to be cool but is not at all see through. I bought these in XXL, the size I usually choose for winter pjs from Reitmans. (Other clothing I am usually XL bottoms and XL or XXL tops). The bottoms fit comfortably. The armholes on the tank top are cut very generously and so the top gapes open too much at the sides. This might not be a problem in smaller sizes. The colour is lovely.