UNITED ARROWS GREEN LABEL RELAXING Black One-Piece Dress Free Size 100% Cotton Made of sturdy material, so you can wear it all year round if you wear an inner layer. I haven't worn it, and it's been stored at home since I bought it. To prevent transparency, there is fabric on the inside of the chest and the armpits, so you can feel secure. You don't have to worry about seeing any side boob.