There are an increasing variety of nursing bras designs, including softcup, underwire, seamless, and lounging styles. Some nursing bras can also serve as a sports bra, allowing a nursing mother to exercise more easily. Some outerwear like tank tops and T-shirts have nursing bras that are built into the garment, and there are also padded and plus-size nursing bras. Some experts advise against wearing an underwire nursing bra because they can restrict the flow of milk and cause mastitis. Most nursing bras have traditionally been white, but manufacturers now offer an increasing selection of colors and styles, including brown, teal, floral, and floral animal prints, and some are accessorized with lace and ribbon.