T-shirt bras are a type of contoured cup bra. They don’t have seams across the cup, this is the main thing you are trying to avoid as it will show though with tight and revealing fabric. The foam lined cups will also help smooth out the shape of nipples, if you need extra protection for this you can combine a bra with nipple covers.
A T-shirt bra has seamless contour cups that are designed to give a smooth look under tight or lightweight fabric. The cups are lightly padded to stop the shape of your nipples showing through. If you don’t want to add any size to your breasts look for ones that are thinly padded through the cup but not padded underneath like a push-up bra is.Read more