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The Brassiere: Construction and fit
A brassiere usually consists of two cups for breasts, a centre panel, a band running around the torso under the bust, and a shoulder strap for each side. Brassieres are typically made of a fabric, such as cotton or polyester. Spandex and lace are also often used for various parts of the bra. The cups for the breasts may be reinforced by underwires made of metal originally, but mainly plastic now. The bra is usually fastened with a hook fastener on the band, typically at the back. In some bras the fastener is in the front, between the cups. Others are pulled on over the head and have no fasteners at all.
Some bras contain padding, designed either to increase comfort, to conceal the nipples, or to make the breasts appear larger. Breast pads, commonly known as "falsies" or "cutlets", are sometimes worn between the breasts and the bra to create the illusion of a larger cup size. Push-up bras in particular are designed to enhance the cleavage and use padding and the cut of the pattern to achieve this effect.
Fitting
The backstrap (band) and cups should provide most of the support, rather than the shoulder straps, which are responsible for a number of health problems (see Mechanical principles, below).
- When viewed from the side, the strap that runs around the body should be horizontal, should not ride up the back, and should be firm but comfortable.
- The underwires at the front should lie flat against the rib cage (not the breast), along the infra-mammary fold, and should not dig in to the chest or the breasts, rub or poke out at the front.
- The breasts should be enclosed by the cups and there should be a smooth line where the fabric at the top of the cup ends.
- There should not be a ridge or any bulging over the top or sides of the cups, even with a low-cut style such as the balconette bra.
Mechanical principles
A pair of breasts can weigh several kilograms. For instance a pair of "D cup" breasts may weigh 15-23 pounds (7-10 kg), dependent on band and cup size. One of the principal functions of a bra is to elevate and "support" the breasts, that is, to raise them from their normal position lying against the chest wall. The bra's shoulder strap should bear little weight. This is considered the defining characteristic of the bra: supporting the weight from the back and shoulders, as opposed to lift from below (as corsets do).
Over-reliance on the platform (backstrap) for support will lead to undue compression of the breasts, so much of the weight tends to be carried by the shoulder strap, particularly for larger breasts. The major engineering weakness of the bra is that it acts as a pulley, transferring the weight of the breasts from the lower chest wall to higher structures such as the back, shoulder, neck, and head. This can result in pain and injury in those structures, especially for women with pendulous breasts.
Size and measurement
The comfort and function of any given bra is highly dependent on the correct size and fit. A large range of sizes are available to cater to the wide variety in the size of women's breasts and bodies. Bra sizes typically vary in two ways: the volume of the cups that fit over the breast, and the length of the back strap that goes around the body. It is essential that the bra fit correctly in both of these dimensions. There is typically some ability to adjust the band size, since bras usually have three or four alternative sets of fastening hooks. The shoulder straps of a bra are also almost always adjustable. The size of women's breasts is often expressed in terms of her usual bra size.
Measurement systems
Although all bras are labeled by size, many women find that the only way to obtain a bra that fits properly and achieves the effect they want is by trial and error with each bra type, model and brand. This method is the most reliable.
Though many countries use the metric system, the majority of nations still use imperial units to determine the underband size of the bra itself.
There are several methods which may be used to provide an approximate size by taking measurements. However, bra sizing systems differ widely between countries, between manufacturers, and between brands and designs, which can create many problems. Many researchers have demonstrated that these problems arise because fit requires knowing the breast volume, not the body circumference (the distance around the body), which is what is actually measured. Although bra sizing uses the circumference to estimate the volume, this has been shown to be highly unreliable.
The size of a bra is commonly described by two values. The first is the band size (underband), a number based on the circumference of the chest under the bust, excluding the breasts. The second is the cup size given by a letter of the alphabet, and relating to the volume of the breasts themselves. For example, a 30D bra is for a 30-size band and a D-size cup. Cup sizes typically start with A, the smallest, and increase alphabetically. A double lettering system may also be used, e.g. DDD for F or AA for a size smaller than A.
Band size is usually determined by measuring body circumference under the breasts as tight as possible. A second measurement is a loose fit taken of the chest circumference over the fullest part of the breasts (overbust). The cup size can then be calculated with tables or a conversion tool from the difference between these two measurements.
The mean underband circumference in the UK is 34 inches (86 cm). For the overbust measurement, this is 40 inches (101 cm), for women 18-64 years.
Copyright: This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on Brassiere.