The winning dress "will be seen on Oscar night probably more than any other gown on the red carpet," said Oscar fashion coordinator Patty Fox. She and show producers Laurence Mark and Bill Condon selected the competing designers.
Moire Conroy, Alan Del Rosario, Sam Kori George, Marianne Kooimans, Maria Pinto, Nicolas Putvinski and Robert Rodriguez each had about three weeks to design their dress.
Del Rosario, who already counts Michelle Pfeiffer and Debra Messing among his clients, said he was inspired by "old Hollywood glamor" when creating his strapless silk-and-lace mermaid gown.
"The Oscars is all-time glamour," he said. "It's one of those events when a woman can go all out."
Maria Pinto, famous for making Michelle Obama's Inauguration Day dress, called her Oscar entry "modern Marie Antoinette." The strapless silver column "is a study of control and release," she said, noting that pleats at the waist shape a makeshift bustle in back.
Putvinski cited New York City skyscrapers as the inspiration for his flowing white gown with folds of silver across the front. Rodriguez also chose white, looking to Grace Kelly as a muse for his silk Grecian column accented with an asymmetrical black strap.
Conroy was inspired by the '60s summer of love for her floaty gray chiffon design, while George was inspired by champagne - specifically the Taittinger girl - for his strapless silver crepe gown adorned with handmade orchids. Kooimans showed an intricately embroidered, one-shouldered dress dripping with antique diamond brooches.
Oscar-worthy gems decorated each of the dresses. Neil Lane, a red-carpet regular who has worked with Marisa Tomei and Angelina Jolie, said he expects vintage looks and subdued glamour at the Oscars this year.
"Everything is classical," he said. "Everything goes back to the golden days of Hollywood."
Fox said that while she didn't offer the design contestants any guidelines, she hoped they'd embrace classic colors and styles. "All the fashion gods were with us," she said.
Fans can vote online for their favorite gown until Feb. 17. The winner of "Oscars Designer Challenge" will be announced during the red-carpet show before the Feb. 22 Academy Awards.
Meanwhile, other Oscar fashion preparations were under way at a penthouse on nearby Rodeo Drive. That's where Spanx, the body-shaping undergarments favored by Beyonce, Kate Winslet, Anne Hathaway and dozens of other Hollywood beauties, set up its annual awards-season suite. So many stylists request the tummy-flattening, hip-slimming underthings this time of year that the Atlanta-based company comes to Los Angeles to dole out boxloads of products in person, said spokeswoman Maggie Adams.
A rep for Tomei and Jessica Biel was among the arrive Tuesday, collecting slimmers in the company's smallest size.