When it came time to create the fashions for The Great Gatsby‘s leading lady, costume designer Catherine Martinneeded little more inspiration than the woman behind Daisy Buchanan: Carey Mulligan.

“The portrayal of Daisy by Carey really opened my eyes to who that character was,” Martin recently told Celebuzz during an afternoon at the The Fitzgerald Suite at the Plaza Hotel, which she designed in collaboration with the New York City landmark. “I think she is quite difficult to understand as a modern woman. You can’t understand why she ditches Gatsby.”

But masterfully brought to life by Mulligan, the convoluted character of Daisy – first created by iconic American novelist F. Scott Fitzgerald – suddenly made sense.

“I think what Carey did is she made you understand that she was…a woman of her time,” Martin continued. “She was brought up to be a rich man’s wife, and the day she became Tom Buchanan’s wife was the best and the worst day of her life. It’s the day she basically assumed the role that everybody wanted her to assume.”

“But after that, there was nothing left,” Martin explained. “She would never fulfill her potential as a person. I think Carey’s Daisy absolutely expresses that. Certainly, her characterization helped me immensely in how we developed the clothes.”

Hear more from Martin – in the videos above and below – on her costume design, how she created a faux Plaza suite for the film’s climactic argument scene, and how she fused reality and fantasy in the The Fitzgerald Suite.

Relive The Great Gatsby by picking up Blu-ray Combo Pack (with HD Digital Download), in stores now.