In any style, quality counts in lingerie

Boston bartender Nicolas Giraldo knows his lingerie.

Not just because the 28-year-old bachelor is a self described "connoisseur of women" but also because he sells his own line of intimate apparel.

Understanding underwear is an art, says Giraldo, a Suffolk College grad who studied the $9.1 billion dollar undergarment market before launching an online store, WowUnderwear.com this past summer. "Not all lingerie is created equal," he says. "We've gone beyond your mother's white Playtex bra to an era when everything's, uh, busting out."

Indeed, retailers as varied as Gap, American Eagle Outfitters, and Chico's, are challenging the ubiquitous pink profiteer, Victoria's Secret. In other words, you can buy bra and panty sets practically anywhere, although a $383 La Perla thong bodysuit "doesn't quite have the same impact" as, say, a $12.99 nightie from Target, says Giraldo.

But how does a well-intentioned male shopper navigate padded bras, garter belts, and underwires without getting entangled in a G-string on his way to the cash register?

First: Know her size. "Buying a bra is not like playing bingo," says Christine Lawless, owner of Newbury Street's Lingerie Studio. "30C? 34B? You need to do your homework."

A reconnaissance mission to her panty drawer should do the trick, says Brenna Graham of Beacon Hill's intimate boutique, French Dressing, who warns male shoppers that bra cups range from AA to GG. "When in doubt, a chemise is easier to size," says Graham.

Colors have messages too. Red, black, and white are standard "I think you're sexy" hues, Graham says. Animal prints are "a bit tacky but acceptable in a quality piece," while ice blue, pink, lemon, and tangerine send a "fun message," she notes.

Prices can range from hundreds of dollars for luxurious European craftsmanship by Wolford's or La Perla ("the Ferrari of lingerie," says Giraldo) to a few dollars for a shrink-wrapped six-pack of undies. "Don't be that kind of guy," warns Giraldo. "The cheap stuff will do more harm than good for your relationship."

During a recent visit to Victoria's Secret at Copley Place, Giraldo browsed the racks offering suggestions on what to buy.

"I like to buy a camisole for women," he says. "It's a sexy look she can wear by itself or under a shirt."

Heading to a display of panties, he says: "Of course, you can never go wrong with several nice pair of thongs or bikini underwear."

Victoria's Secret spokeswoman Martha McGuinness says the chain's new Sexy Sheers bra and panties "are blowing off the shelves" because of their brightly colored lace and leopard print. Customers have also taken to the latest manufacturing techniques -- laser cut, seamless, label-free, and stitch-free that "result in completely smooth, sexy, invisible silhouette under clothing," she says.

But whether it's a leopard print teddy or a lace bra, "make sure you give lingerie as a gift for her, not on her," says Giraldo. "That means something so comfortable and soft that it's like wearing a hug."

So what kinds of lingerie should one have? Rebecca Apsan, author of "The Lingerie Handbook," offers a practical gift list of boudoir basics: a pretty robe, long gown, bra and panty set, garter belt, thong, and a baby doll or camisole with matching shorts.

To read more about French Dressing and its Thong of the Month Club, see today's Boston Globe Magazine.