THEY ARE either the greatest invention since liposuction or the worst since the chastity belt.
In lingerie departments across the country, women of all ages, shapes and sizes are buying new types of foundation garments that promise to provide the control and shape of girdles, corsets and merry widows of the past but without the pain.
It's a combination of fashion with foundations that is stirring up sales for many manufacturers. From 1989 to 1990, sales of body-shaping garments increased by more than $25 million, from $324 million to $350 million, according to the Intimate Apparel Council.
Part of their success owes to designs that incorporate better construction and fabrics. These aren't the 1950s latex rubber 24-hour girdles that were actually comfortable for 2.4 minutes. With new applications of the breathable microfibers and stretchable Lycra blends, the new girdles, slips, control-top hose and tights are giving women more control of their bodies.
Or are they?
Opponents say the reappearance of garments that reshape and constrict a woman's body shows that the fashion cycle is snapping backward like a stretched elastic waistband.
Proponents say they provide more women the opportunity to wear today's fashionably clingy styles, without worrying about lines and lumps.
* The trendy New York department store Bloomingdale's has opened a new lingerie section that focuses on body-shaping garments push-up bras, shorts and slips made from extra-strong Lycra and boned elastic strips called waist cinchers.
* One of the best-selling sections of the Frederick's of Hollywood catalog features body-shaping garments, including Power Pants, leggings made of high-strength spandex, said Ellen Appel, a Frederick's spokeswoman.
* A high-powered Lycra half-slip with a built-in panty, the Slim Liner by Lady Lynne, has brought millions in sales to the 53-year-old New York lingerie company and revived other companies that offer similar products, industry experts said.
* Designer Donna Karan has introduced $12.50 to $18 Body Toners, control-top pantyhose that extend the power panel to the thighs.
"The whole category of foundations and body-shaping garments is exploding right now," said Karen Bromley, a spokeswoman for the Intimate Apparel Council in New York.
"The surge started about a year ago and that had to do with innovative styling. The slip was a dead issue, but by adding Lycra and making it into a body-shaping garment, the whole industry was revolutionized," Bromley said.
Sleek, tight and short Lycra slips like the Hip Slip and the Fashion Shaper by Subtract allow a woman to wear those unforgiving stretchy dresses without showing her panty lines or non-aerobicized figure.
But they don't signal fashion's acceptance of the curvy, feminine form.
"We've always felt that the fashion industry was misogynist. You can't run from a rapist in pumps," said Tammy Bruce, president of the Los Angeles Chapter of the National Organization for Women.
"Women have got to get out of the mind-set that they have to unnaturally change their bodies to fit what the boys think they should look like.
"These are done, I feel very strongly, in a direct conspiratorial fashion to make women be and feel uncomfortable, to make them feel they are something they are not," she said.
That wasn't exactly what Steve Aronoff, owner of Lady Lynne Lingerie, had in mind when his New York firm started selling the stretchy control slips.
"We are not looking to change the shape of women and make them into tiny little things like binding their feet," he said. "It does allow you to go out to eat without looking bloated afterward."
Such is the power of the Slim Liner slip that his wife was able to fit into a dress one size smaller than normal, he said.
Some wearers of the new garments aren't at all conflicted about the message the garments may send.
"I'm a total feminist and I love it," said Jackie Falk, a Century City resident majoring in the study of men's and women's roles in society at the University of Southern California.
"I don't think it's repression. You can wear whatever you want to. And it's also really comfortable," Falk said. She wears hers dancing.
Ordinary underwear just doesn't work under the tighter fashions, said Mary O'Neill of Sherman Oaks.
"The problem with regular slips is that they ride up, especially under tighter dresses," she said. The figure-shaping properties of the garments has sparked the interest of O'Neill, mother of a 4-month-old daughter.
"Things don't fit quite the same after a baby," O'Neill said.
The reality of fashion is that virtually every new fashion requires a new foundation, except that this one wasn't invented in time for the onset of clingy stretch dresses.
"Foundations are like the reverse of accessories," said Martin Fung, a fashion designer teacher at the Fashion Institute of Design and Merchandising in Los Angeles. "It adds the finishing touch.