Shapewear has long been kept under wraps, often viewed as taboo or shameful for a woman to admit to wearing. Now it not only is commonplace for a night out but is also, in some cases, being promoted to outerwear.

Just about anything worn under clothing to enhance a figure or hide perceived flaws can be considered shapewear. Shapewear’s history dates back hundreds of years, in the form of corsets, stays and petticoats. Since then, the popularity of shapewear, available at Los Gatos’ Romantiques Lingerie and elsewhere, has ebbed and flowed: in the 20th century alone, it waned in popularity during the flapper years, then was made almost mandatory in the World War II era on through the early ’60s. Now that another period of public disinterest in (and even scorn for) shapewear is ending, it’s time for it to take hold of women’s silhouettes once again.

Ever since AMC’s Mad Men, set in the early 1960s, hit the air in 2007, the fashion media has been buzzing about the “Mad Men look.” Mad Men quickly became famous for its unparalleled attention to detail and accuracy in the costuming and set design, portraying characters in more subdued period clothing rather than in cartoonish beehives and cat-eye glasses.

The show proved to be a huge influence on women’s fashion in the years following its debut, prompting designers to recall the days of tighter, curve-hugging, ultrafeminine clothing. The cropped cardigans and pencil dresses emphasize female curves but aren’t always flattering when made with today’s clingy fabrics.

Like the Mad Men–inspired dresses on the racks today, shapewear has changed with the times. Streamlined and smooth, modern shapewear is more commonly made with elastics and thick nylon fabrics, rather than the metal hardware that was embedded in the girdles and supports in the ’40s and ’50s.

Spanxis the top contender in the field, producing a vast range of products to slim women from head to toe, including bust reducers, tummy trimmers and the original smoothing tights. Almost every major lingerie brand produces some kind of shapewear in addition to bras and panties. In early 2010, Spanx even introduced a slimming tank top for men, and shortly after, a handful of other companies soon began producing their take on it.

Even though shapewear is being used as a secret weapon under clothing, it’s also garnering a lot of attention/criticism, as it is being incorporated into celebrities’ ensembles as the focal point of many outfits. Katy Perry recently stirred up controversy by appearing on Sesame Street in a corsetlike dress, a segment which was later axed after the clip hit the Internet to outrage from parents who felt the dress emphasized Perry’s figure a little too much.

Kim Kardashian constantly hits the red carpet in structured corset dresses and tops featuring underwire, usually contrasted under a form-fitting men’s blazer or paired with skinny jeans. Kardashian has also made no secret of the shapewear she sports underneath form-fitting outfits, publicly pledging her allegiance to Spanx and Canadian brand Body Wrap.

Almost any major department store has a decent selection of shapewear, ranging from thin elastic tummy-smoothers to girdles. Macy’sand Nordstrom usually have the most varied selections, with smaller retailers like Kohl’s and Target providing the basics. And if you really want it, specialty shops and countless online retailers resell or reproduce classic girdles and waist cinchers.