tag or label is attached or printed onto the bra itself. The completed bras are folded (mechanically or manually), and packaged for shipment. The chest band and cups, not the shoulder straps, are designed to support the weight of women's breasts. Strapless bras rely on an underwire and additional seaming and stiffening panels to support them. The shoulder straps of some sports bras cross over at the back to take the pressure off the shoulders when arms are raised. Manufacturers continually experiment with proprietary frame designs. For example, the Playtex "18-Hour Bra" model utilizes an M-Frame design. Materials Bras were originally made of linen, cotton broadcloth, and twill weaves and sewn using flat-felled or bias-tape seams. They are now made of a variety of materials, including Tricot, Spandex, Spanette, Latex, microfiber, satin, Jacquard, foam, mesh, and lace, which are blended to achieve specific purposes. Spandex, a synthetic fiber with built-in "stretch memory", can be blended with cotton, polyester, or nylon. Mesh is a high-tech synthetic composed of ultra-fine filaments that are tightly knit for smoothness. Sixty to seventy per cent of bras sold in the UK and US have underwired cups. The underwire is made of metal, plastic, or resin. Said the antecedents for underwire in bras date to at least 1893, when Marie Tucek of New York City patented a breast supporter, a sort of early push-up bra made of either metal or cardboard and then covered with fabric. Underwire is built around the perimeter of the cup where it attaches to the band, increasing its rigidity to improve support, lift, and separation. Wirefree or softcup bras have additional seaming and internal reinforcement. By the late 1970s, wire-free bras were emerging both at Hanky Panky and at Hanro in Switzerland. Cosabella in Italy and in France followed in the 1980s, as did Eberjey in the 1990s. Others use padding or shaping materials to enhance bust size or cleavage. Size and fitting In most countries, bras come in a band and cup size, such as 34C; 34 is the chest band, or the measurement around the torso directly underneath the breasts, and C is the cup size, which refers to the volume of the breasts. Most bras are offered in 36 sizes; the Triumph "Doreen" comes in 67 sizes, up to 46J. The cup size varies depending on the band size. A D cup on a 38 band is larger