The summer has brought a host of films in which the costumes have garnered enormous attention. The ethnic alien attire from "Star Wars: Episode I: The Phantom Menace" has been much ballyhooed because of the handwork and time invested in each garment. In particular, Queen Amidala's gowns necessitated thousands of hours of stitching and embroidery for a single bit of royal raiment.

There was enormous buzz surrounding the costumes in the second Austin Powers film, "The Spy Who Shagged Me." Those who promote such things burbled about how the '60s psychedelic secret agent fare in the movie was bound to spark lucrative style trends.

But so far, neither movie has spawned the avalanche of trends that was predicted.

Other recent films that were supposed to be feasts of fashion also were unfulfilling. The ill-fated "Mod Squad" with Claire Danes and Omar Epps was supposed to renew interest in a glossy, hippie style. "The Avengers" was to have sent every female moviegoer lusting after an Emma Peel black leather catsuit. Not only did neither film cause such jubilant imitations; both movies were utterly forgettable. It seems that before a movie can start a trend it first must attract an audience.

In reality, it has been a long time since a film spawned a fashion trend. To be sure, the fashion industry has been enamored of hippie style and of mod fashion over the last few years. But it's more likely the film industry was following fashion's lead than the reverse. After all, Gucci resurrected the mod look long before "Mod Squad" ever hit the cineplexes.

Sure, Uma Thurman got women excited about blood-red nail polish with her role in "Pulp Fiction." But inspiring women to rush out and stock up on Chanel's vamp nail polish--or Revlon's cheaper vixen formula--is a far cry from when Diane Keaton in "Annie Hall" inspired hordes of women to shop the menswear department, or when Clark Gable in "It Happened One Night" had men tossing out their undershirts to imitate his shirt-on-skin style.

Before a film can spawn a fashion trend, a host of elements must come together. The clothes must be more than a scenemaker, as with Queen Elizabeth I's extravagant finale gown in "Shakespeare in Love." They must create a style. Consider Audrey Hepburn in "Breakfast at Tiffany's." It wasn't simply one dress that made so many women want to dress like Hepburn. Rather, it was Holly Golightly's overall style, from her multiple strands of baubles, to her enormous picture hat, to her streaked hair, to her glamorous sunglasses.

But more important than style, says Sandy Schreier, author of "Hollywood Dressed & Undressed," is star power. "In 'Saturday Night Fever,' John Travolta--the way he walked and moved--he could have been wearing anything and it would have become a trend," Schreier says.

Before a film can influence fashion, Schreier says, it has to conjure romance and desire. The audience has to want to be the characters on the screen. "Does anybody really want to be Austin Powers?" Schreier wonders. "But the insurance agent in 'The Thomas Crown Affair' played by Faye Dunaway, she was sexy and smart. . . . Meryl Streep playing Isak Dinesen [in 'Out of Africa'], she was smart and she got Robert Redford."

And of course, "Out of Africa" inspired folks to dress as if they were going on safari even if they were only headed to the market.

The symbiotic relationship between Hollywood and fashion is well documented. Fashion has helped many a Hollywood starlet build an image. "American Gigolo" made designer Giorgio Armani a household name and people wanted to wear his clothes. But Jean-Paul Gaultier's work in "The Cook, the Thief, His Wife and Her Lover" failed to make the designer much of a commodity in middle America. And why didn't "The English Patient" spark the same sort of love affair with desert chic as "Out of Africa"? The answer could be timing. Consumers simply weren't interested in dressing in a palette of beige and ivory just then. Or, it could be because the main characters weren't particularly likable; they were even boring.

When actors wear a designer's clothes to walk a red carpet at a gala opening, the message is clear: Clothes equal glamour. When they're placed in a movie, the message becomes a complicated mix of characters, story line, personality and magic. And that is a far more difficult mixture to control.

CAPTION: Onscreen style, clockwise from top left: Richard Gere in "American Gigolo"; Uma Thurman and Ralph Fiennes in "The Avengers"; John Travolta in "Saturday Night Fever"; Heather Graham and Mike Myers in "The Spy Who Shagged Me"; Diane Keaton and Woody Allen in "Annie Hall"; and Natalie Portman in "Star Wars: Episode I."