In Bikini Science a brassière is defined as a close-fitting soutien-gorge with cups shaped to support the bust, two shoulder straps, and one torso strap. It is often fastened in the center back, but may also fasten in front and or have no fasteners. A brassière differs from a halter in the position of straps (shoulder as opposed to neck), and from a bandeau, which is similar but strapless. The wearer of a brassière is called a brassièreite.
The brassière provides maximum topological complexity of a soutien-gorge, indeed, the changings of the bra are equivalent to the changings of a shirt, vest, camisole, croptop, and tankini. With two shoulder straps and one torso strap, the bra has four edges, one more than the halter, and two more than the bandeau.
Several different types of brassières are treated as separate species, largely because each plays a specific role in the evolution of swimsuit silhouettes. These include the shelf bra, popularized during the early 1940s, the minimizer bra (which seeks to flatten and de-emphasize full bustlines), the underwired push-up bra (first popularized during the 1960s), the string bra (analogous to the string halter), the Spandex exercise bra or tankini of the 1980s, and the salacious demi-bra. This section focuses primarily on the bulkier cloth bra popularized in the late 1940s and 1950s.
The Bra Reconfigured
Because it is inherently topologically rich to begin with, the bra may be reconfigured into most other species of soutien-gorge. If the shoulder straps detach in the back they may be tied behind the neck, creating a halter silhouette. The bra straps may also be unfastened or slid off the shoulder and arm to convert the bra into a strapless, or bandeau species.
Fastening details play a big role in bra design, with a wide variety of fasteners in use. Either or both of the shoulder straps and the torso strap may or may not have fasteners. The shoulder straps may be independently unfastened, in the front or the back, and the torso strap may be designed to fasten in the front or the back. Shoulder straps can also be exited via strapoffs.
As with halter, there is a wide opportunity of sequence of doff and don, with a basic division occurring between brassièreites who put their arms in the garment first and then hook it, and those who encase the garment around their torsos before entering the shoulder straps (or fastening them). The complexity of the bra doff and don is further exacerbated by practices such as the brassièreite who puts the bra on around the torso but backward, fastening the backstrap in the front, and then rotating the garment around 180 degrees so the back fastener is in back, and then pulling the bra up over the breasts and entering the shoulder straps. On the beach brassièreite may also do strap play and fastening lying on her belly or back.
The brassière is a French underwear invention, and the first usage of the term in America is about 1907. Initially a woman's underbodice worn to support the breasts, the bra migrates to the theater stage in the early 20th century (e.g., AZ191710) before it emerges in swimwear with great caution in the early 1930s (LA3303) and then with more confidence in the early 1940s, drawing on influences from underwear and theater costumes.
The first major bra design in swimwear is the shelf bra, which incorporates a band of fabric below the breasts which provides both midriff coverage as well as breast support.
During the 1950s the bra consolidates; it looses the facing below the breasts and employs darts to mold cups (LT194610). The two cups of the bra are constructed with several pieces of fabric and may be tailored, sheer, lacy or stretch. Cup sizes enable the designer to determine the cups's exact shape and size.
During the early 1960s the straps narrow and the garment becomes less constructed with darts and pattern providing shape (SS6410). By the late 1960s the bra begins to incorporate space-age materials, especially embedded underwires in the cups (SS6510), creating the push-up bra silhouette. Other 1960s foundation includes molded and seamless cups that provide a fixed shape and smooth cone look. Padded cups increase the apparent breast size.
In the 1970s the bra practically becomes extinct as a swimsuit species, driven out by the unconstructed string halter. By the late 1980s a small percentage of women adopt similarly-styled string bras to wear with tangas (FL8601, CI8901), but even throughout the 1980s these brassièreite provide an exception to the rule. Bra-style tops also can combine fuller coverage, open-mesh, and ususual backs (PB87CA).
The Spandex Stretch Bra
The late 1980s Spandex bra marks a return to two-shoulder silhouette. Unlike 1940s brassières, the Spandex bra (like the soft triangle halter) is entirely unconstructed, relying entirely on stretch fabric to provide support for exercise activities like jogging and aerobics. This tankini design may be conservative, with a small armhole and a high neckline, or libertine, with large armholes and a scooped neck and a low neckline. Because the Spandex hugs the breasts the effect is a smooth, sleek look.
Not until the late 1980s and early 1990s does the bra reappear on the beach (SE9188), and not until the late 1990s does foundation and the push-up bra again play a role.
Another 1990s development is a gradual breakdown between the bra as underwear and the bra as outerwear--both on the beach as well as in the nightclub and on the street. This is driven by women who consider exposing bra straps as normal fashion, as well as by just wearing underwear bras in public.
The cloth brassière and the nombril are the emerging silhouette of the bikini in the early 1950s.