Modern swimwear[ edit ] The bandeau emerged as the top part of a two-piece swimsuit during the s. In the s the bandeau incorporated foundation so as to structure or improve the contours of the body, while still retaining a relatively simple circle or band shape, emphasizing the bare midriff. Its popularity in swimwear declined during the string bikini era, but it reappeared in the s, especially with Spandex and other stretch fabric blends. Side stays, v-wire in the center front, O-rings, and the twisted top are popular design elements. It may be fastened in the front or back or be sufficiently elastic so as not to need a fastener at all. A bandeau may come with a detachable halter strap, for extra support.