2012 Costume Institute Gala at the Metropolitan Museum of Art

Nina Dobrev in a one-shoulder Donna Karan gown.   (Evan Agostini / Associated Press)

Beyonce Knowles in a Givenchy Haute Couture gown.  (Dimitrios Kambouris / Getty Images)

Rihanna in a black leather gown by Tom Ford.   (Larry Busacca / Getty Images)

Diane Kruger in a purple Prada gown.   (Dimitrios Kambouris / Getty Images)

Leighton Meester in Marchesa.   (Larry Busacca / Getty Images)

Rosario Dawson in Calvin Klein.   (Larry Busacca / Getty Images)

Actress Hilary Swank in Michael Kors.   (Dimitrios Kambouris / Getty Images)

Gwyneth Paltrow in a Prada dress and jewelry by Anna Hu Haute Joallerie.  (Dimitrios Kambouris / Getty Images)

Victoria Justice in McQ Alexander McQueen.  (Dimitrios Kambouris / Getty Images)

Actress Elizabeth Banks in a Mary Katrantzou dress.   (Dimitrios Kambouris / Getty Images)

January Jones in a custom Atelier Versace bustier dress.   (Justin Lane / EPA )

Marion Cotillard in Christian Dior.   (Dimitrios Kambouris / Getty Images)

Dianna Agron in Carolina Herrera.   (Larry Busacca / Getty Images)

Renee Zellweger in an Emilio Pucci silk gown.  (Dimitrios Kambouris / Getty Images)

Ginnifer Goodwin wearing a tangerine Monique Lhuillier gown.   (Larry Busacca / Getty Images)

Lea Michele wearing Diane von Furstenberg.   (Dimitrios Kambouris / Getty Images)

Amber Valletta in a Prada silk gown.   (Larry Busacca / Getty Images)

Cate Blanchett in Alexander McQueen.   (Charles Sykes / Associated Press)

Kate Bosworth in a Prada feather dress.   (Dimitrios Kambouris / Getty Images)

Chloe Sevigny in a mod Miu Miu dress.   (Justin Lane / EPA)

Jessica Chastain in a satin Louis Vuitton dress.   (Justin Lane / EPA)

Kristen Stewart in Balenciaga.   (Larry Busacca / Getty Images)

Jessica Biel in Prada.   (Charles Sykes / Associated Press)

Lily Collins wearing a Valentino dress.   (Larry Busacca / Getty Images)

Sarah Jessica Parker in Valentino.   (Charles Sykes / Associated Press)

Emma Roberts in a belted Escada gown.   (Larry Busacca / Getty Images)

Carey Mulligan in Prada.   (Charles Sykes / Associated Press)

Emma Stone in Lanvin.   (Charles Sykes / Associated Press)

Gisele Bundchen in Givenchy.   (Charles Sykes / Associated Press)

John Krasinski, left and Emily Blunt, both in Calvin Klein.   (Charles Sykes / Associated Press)

Heidi Klum in Escada.   (Charles Sykes / Associated Press)

Rachel Zoe, left and model Karolina Kurkova, wearing a look designed by Zoe.   (Dimitrios Kambouris / Getty Images)

Kristen Wiig in a dress and shoes by Stella McCartney.   (Charles Sykes / Associated Press)

Shailene Woodley, left, wearing Christopher Kane, with the designer Christopher Kane, right.   (Larry Busacca / Getty Images)

Designer Riccardo Tisci, left and actress Rooney Mara, wearing a design by Tisci for Givenchy.   (Dimitrios Kambouris / Getty Images)

Brooklyn Decker wearing a gown by Tory Burch.   (Dimitrios Kambouris / Getty Images)

Rosie Huntington-Whiteley wearing a Burberry gown and jewelry by Irene Neuwirth.  (Charles Sykes / Associated Press)

Milla Jovovich in Prada with a Prada clutch.   (Charles Sykes / Associated Press)

Jessica Alba in a metallic Michael Kors dress.   (Charles Sykes / Associated Press)

Julianne Hough in pink Carolina Herrera.   (Charles Sykes / Associated Press)

Christina Ricci in a Thakoon dress with bow detail.   (Charles Sykes / Associated Press)

Sofia Vergara in David Meister.  (Charles Sykes / Associated Press)

Scarlett Johansson in Dolce & Gabbana.  (Dimitrios Kambouris / Getty Images)

Claire Danes in a gown by J. Mendel.  (Charles Sykes / Associated Press)

Solange Knowles wearing Rachel Roy.   (Charles Sykes / Associated Press)

Florence Welch in Alexander McQueen.  (Larry Busacca / Getty Images)

Camilla Belle in a Ralph Lauren Collection ivory tulle gown.   (Evan Agostini / Associated Press)

Brooke Shields wearing J Mendel.  (Evan Agostini / Associated Press)

Lana Del Rey in a gown by Joseph Altuzarra.  (Charles Sykes / Associated Press)

Anna Wintour chose Prada for her gown.   (Charles Sykes / Associated Press)