Underwear isn’t something many people overthink. You might feel differently, though, after seeing Undressed: A History of Fashion in Underwear. The exhibit, which originated at London’s Victoria and Albert Museum and makes its only North American stop at The Frick Pittsburgh, explores some three centuries of undergarment hows, whys and why nots.

The exhibit, which opens Sat., Oct. 21, includes nearly 250 separate objects, from historical stays and corsets to early bras and contemporary lingerie. Underwear’s uses are considered in the contexts of health and hygiene, fashion and more. Subcategories explore hosiery, luxury lingerie, loungewear and present-day designers’ penchant for using underwear as outerwear.

Today, anything goes beneath, but it wasn’t always so. Stays — fully-boned, lace-up bodices — were once de rigueur for respectable women in public. One of the oldest pieces in Undressed, says Frick chief curator Sarah J. Hall, is a hand-made stay found in the cottage of an 18th-century working woman. Stays were precursors to corsets, of which Undressed has many; these infamous and often ornate garments are remembered partly for their harmful health effects (which the exhibit notes), but at the time were considered more comfortable than stays.

While people today have more, and more practical underwear options, echoes of the past remain in garments like “waist-trainers,” employed by the likes of Kim Kardashian to achieve extreme hourglass shapes.

While most of Undressed focuses on women’s unmentionables, men’s garments are represented too, says Hall. Examples range from a circa-1840 male corset to modern “body-enhancing” underwear, and the style of leaving visible the designer-name-bearing waistband of one’s tighty-whities.

Undressed also examines the cultural context surrounding things like bust bodices and girdles, from changing standards of physical beauty and the rise of a middle class to the growth of consumer culture and the technology behind new materials.

Even if you know underwear cold, you’re likely to find a surprise or two. Hall’s favorite pieces, for example, include an early example of “performance underwear”: a down-filled, paisley-patterned petticoat from 1860 Ireland that handily combines fashion and function.

At the time, of course, no one would have seen the petticoat but its wearer. “It’s really kind of fun to get to look at the things we don’t look at that often,” says Hall.