Slim in the swim with these suits

It's no longer a stretch to say certain bathing suits have a slimming effect. Tackling women's body-image insecurities head-on instead of burying them under a lot of extra fabric, the swimwear industry now has its MiracleSuit, SlimSuit and SlenderSuit, among others.

"I firmly believe the explosion is a combination of women wanting coverage and control," says Michele Casper, swim spokeswoman at Lands' End, which this year differentiates between three levels of slimming suits from moderate shaping to power control.

Lessons learned in Lycra, linings and lingerie construction are also key factors.

The MiracleSuit boasts a high-elasticity fabric with a high Lycra content that constantly wants to pull the swimsuit back into a taught shape and it takes the body inside with it, explains design director Ed Tucker.

"A woman puts the suit on and it starts to compress to a point where a woman feels very supportive," he says. "She feels more confident as she's walking feeling like things aren't moving that she doesn't want to move."

However, he adds, it's not so tight that skin oozes out elsewhere. "It's not like wearing a girdle. It compresses you, but it's not uncomfortable. It makes you feel firmer."

Lands' End treats its fabric with silicon, very much with the stomach, rear and side love-handles in mind, Casper says. "You feel control built right in without extra weight or a cumbersome feel. Fabric technology has come so far."

She thinks it's market-driven: Each year, her company has seen more interest in slimming suits and it complements the movement back toward one-piece silhouettes.

"The ability to look one size smaller is appealing to a lot of women no matter what size you are," she says.

Starting out with the proper size, much like a bra, often sets you off on the most flattering path, designers say.

There shouldn't be any part of the swimsuit cutting into the body at all don't kid yourself that you can hide it, says Daniela Manfredi, Victoria's Secret swimwear designer. She's fond of working with a heat-sealed adhesive at the edges of the suit that work more like a tape than the old elastic arm and leg holes that pose a greater risk of "popping out."

Using the brand's insight into bra construction, Manfredi says there's almost no reason not to have an underwire in the bust of a swimsuit, even a bandeau top. "We have really good ways of hiding them."

Carol Wior, creator of the patented SlimSuit, got into the swimwear business after life as a dress designer when she was on vacation after the birth of her daughter and didn't like the sagging she saw, especially around her bustline.

Her secret weapon now, she says, is a full-suit lining that attaches to an underwire bra inset. "If your bust gets lifted up, it slims the waistline," she explains.

The interior fabric was calculated with two stretch factors in mind: the width of the body needed to expand and then contract to provide control, and the height needed more give so it would be comfortable as a woman moved around.

"It's like buying a jacket. A well-lined jacket hangs better," Wior observes.

Don't underestimate the comfort factor, either, says Pamella Protzel Scott, designer of Ella Moss, a label now working with a soft nylon Spandex that she describes as feeling like a "second skin."

"You have to keep in mind stretch and comfort as well as sheerness and sustainability," she says.

And, adds Manfredi, check for flat seams, little bulk in the body and matte finishes. "Shine can be dangerous in a fabric. You'll be in bright sunlight and shine is less flattering. A solid or small pattern works best."