T-shirt bras feature a sleek discreet cup design, which is suitable to wear under t-shirts and other thinner garments that require a smooth look. T-shirt bras can be either padded or non-padded, so make sure to check this detail in the product information page before purchasing. Some t-shirt bras are made of lightly padded spacer foam material. T-shirt bras can feature some flat seams, but they can also be completely seamless – seamless t-shirt bras are called moulded bras which are the most discreet option under clothing.