When Kate Winslet took to the red carpet earlier this month at the Venice Film Festival in a sporty but sexy dress, jaws dropped over her va-va-voom curves. Though the Oscar winner has never been shy about embracing her voluptuous figure, her exaggerated hourglass form was actually courtesy of her dress — a color-blocked Bicolour Octavia number by Stella McCartney.

“It’s like retouching your body with a frock,” says celebrity stylist June Ambrose of the sheath, which retails for $1,595. The figure-flattering number­ — one of the “optical illusion” dresses from the designer’s fall collection — focuses the eye with a contoured front panel while its black sides seem to disappear, creating a deceptively smaller waistline.

Winslet isn’t the only A-lister to have noted the dress’ cunning trickery.

Celebrities such as La La Anthony and Gloria Estefan have both rocked the sexy dress, while “The X Factor” judge Nicole Scherzinger graced the cover of InStyle UK in the shaded wonder. Liv Tyler wore an electric cobalt-and-black version earlier this year.

“This has become one of the biggest dresses of the year,” says Sasha Charnin Morrison, the fashion director of Us Weekly. “It’s a body-conscious dress that is so clever, and it’s from a major designer. All of the groovy girls wear Stella. Everyone wants to wear her now.”

The shape-shifting dress hung in the window of McCartney’s Meatpacking District store at the start of New York Fashion Week this month and sold out days after the shows ended. Currently out of stock on the company’s Web site, the dress is expected to arrive in new shipments by the third week in October.

Click here for the full report from the New York Post.