Bras, like lingerie in general, are common fetish objects. Their function in covering the breasts also serves to hide them from view, which arouses interest. The fetish for breasts transfers to the object that obscures them.
Bras usually have straps that go over the shoulders to help with support. A glimpse of the bra straps may be considered erotic by some people. Since the 1980s, there have been recurring minor fashion trends of leaving bra straps unconcealed. Strapless or bandeau bras are produced for people who wish to have bare shoulders.
One way to emphasize the bra while technically covering it is to wear a black bra beneath a thin semi-diaphanous white blouse. Also, some sports bras are designed to be worn without outer covering.
Some bras are specifically designed to enhance the wearer's cleavage.
Although all types of bras can become fetish objects, some types are specifically designed as fetish wear. Some of these are:
- Bras made of sheer or see-through material
- Bras made with unusual materials, such as leather, rubber, PVC or fur
- Bras with cutouts over a portion of the cup, such as those revealing the nipple and areola.
- Bras with exaggerated conical shapes (e.g., the "bullet" bra)
- Bras ornamented with lace, often in a colour contrasting with the bra, such as white on black
The cups that hold the breasts vary in size to accommodate different wearers. Most adult females will want A (the smallest) up to D, but smaller (mainly for young girls) and larger cups are available.
The cups are often made of one piece of material with no seams, giving a smoother line under a tight-fitting top. However, two or three part cups give more support, and four part ones may be needed for those with larger breasts.
Front or rear closure
A bra may fasten at the front or the rear; rear is more common. Traditionally, a rear closure has two rows of hook and eye closures and three different positions to allow for adjustment for different chest sizes. Full figure and strapless bras usually have three rows of hook and eye closures for extra strength, but still have three adjustments.
Undoing someone else's rear closure is a potent symbol because you can then access the other person's breasts easily.
A punishment bra is a bra that is designed to make the wearer uncomfortable while it is worn. Punishment bras of varying designs feature in fetish and BDSM fiction but there is no evidence to suggest they are used much in actual BDSM play, a supposition supported by the lack of any on-line retailers selling punishment bras.