T-shirt bras, also known as contour bras, are designed to appear invisible underneath shirts and blouses. Unlike designer lace bras (cut and sew), T-shirt bras are seamless and specifically constructed without ornamentation that may show through some clothing. Soft and moulded cups may help to prevent nipple show through under form-fitting tops.
Elements of a T-shirt bra
Seamless cups: The cups of a T-shirt bra are always seamless. This is what makes this bra style ideal for wearing under thin, lightweight or form-fitting clothing. You just get a smooth, clean finish every time.
Moulded cups: Most T-shirt bras feature moulded cups with a thin layer of foam to help create a rounded shape. When off the body, the cups stay rounded.
Underwires: Most, but not all, T-shirt bras have underwires. This helps support and lift your breasts to give you a rounded silhouette. However, if you’d rather go without underwires, there are wireless t-shirt bra designs.