The most common method of support in bra construction is the use of underwires. Underwires are molding that are sewn into the bra under the cups. Today, underwires are constructed from a variety of materials. They can be made of plastic-coated metal, molded plastic or flexible wire. Some underwire bras offer extra comfort by placing the underwire between layers of fabric. Underwire bras offer good support and lift and are the first choice among women who wear C cups or larger.
Most underwire convertible bras will have wardrobe versatility. Convertible straps are designed to be worn several different ways. Some will be attached at the from of the cup, which allows for less versatility. Most will be detachable at the front and back, allowing you to wear them as halter, criss-crossed, off-the-shoulder and one-shoulder and strapless. Because so many bras are constructed with underwires, it's easy to find a convertible underwire bra style for any size or wardrobe need.