Visible lines were the major panty issue (51.3 percent) in a recent 917-woman survey by Intimacy, the fit-conscious lingerie boutiques. For the smoothest top-to-bottom silhouette, look for a high waist (it should extend right up to your bra) and long, thigh-mastering legs. A microfiber shaper lets knits slide on snaglessly.
You've Got a Curve (center)
This racy black thong is definitely "not your mother's girdle," says Susan Nethero, Intimacy's owner and chief fit stylist (she has stores in Atlanta, Chicago and New York). Today's shapewear, she points out, is so lightweight and flexible that it's incredibly comfortable, confidence boosting, and sexy.
Perk Up (bottom)
Panty legs don't have to be high cut to go unnoticed under knits: Nonbinding edges make this all-in-one do a vanishing act. Detachable straps secure the raised waist to your bra, and there is a subtle cheek separator to avoid that "uni-butt" effect.
Double your exercise pleasure with a copycat underlayer: Choosing a panty that mirrors the shape of your clothes is one of Nethero's key invisibility strategies. Folded edges lie flat; copper-bonded fibers in the fabric work as antimicrobial agents.
High Line (center)
Give thongs a chance (Nethero's rules: Buy a good one—comfort requires more fabric, higher cost—and allow two or three wearings to adjust to the new feeling). This high-tech fabric wicks away moisture from the body, so you won't get soggy while working up a sweat.
Brief Encounter (bottom)
Boy shorts are making a comeback, Nethero says: Full butt coverage prevents unattractive ride-up in back (reason enough for their popularity); unobtrusive edging keeps them looking smooth.
The very low rise keeps these hipsters undetectable, but they're not too skimpy for comfort under tight-fitting jeans. Cool mesh trimmed with wide, stretchy lace bands (which lie smoothly on the body) is luscious for summer—the lingerie equivalent of green-tea ice cream on a hot day.
The Great Lace-Up (center)
A little panty that looks romantic, acts practical: The silky synthetics and well-behaved flat edges guarantee a bump-free ride. Denim is opaque enough to let you play around with your lingerie—it's fun to wear something girly under something tough.
Turning Pink (bottom)
Now that new fabric technology has produced lingerie that won't press the flesh, panties can be more comfortable—but still discreet. A sheer, well-priced microfiber hipster panty gives the derriere decent coverage and has a low-rise waist.
Rosebuds under a skirt: nice ("You don't want an orthopedic-looking foundation garment," Nethero says). A lace boy short has a vintage pinup-girl vibe—the color is "antique" beige—but the thin, second-skin control fabric is comfortably modern.
Join the Firm (center)
"All women have lots of soft tissue, even when we're not overweight," Nethero says. "If your panties grab hold, the lines are going to show." This low-profile shaper has a front panel to control jelly-prone hips and bellies; people with flat-butt issues will love its derriere-enhancing back seam.
Seamless Transition (bottom)
Now you can get thongs and shapewear in one package. A waist-to-hip control panel targets the areas accentuated by the skirt; the longish panty is sheer but strong. Don't worry if you work long hours; finespun microfiber is a flexible companion.
Science has revolutionized lingerie with panties cut out with a laser (because they're microfiber, they won't run or fray), thus eliminating bumpy seams and bulky hems. The deep brown—trust us—will disappear under white because it blends so well with her skin.
You've Got Pale (center)
Made from superthin, razor-cut microfiber, the trim panties here are a good compromise, coverage-wise: roomy enough in back to look good under loosely woven white clothes but light and sleek enough for steamy weather.
Sweet Nothing (bottom)
If you're not yet a thong convert, this is a great try-out idea: It has modest coverage in front and narrow, unobtrusive elastic along the edges.