Over the past few weeks, we’ve seen Carey Mulligan dominate the “Suffragette” press tour in a ruffled Chanel frock, a floral Roland Mouret dress, and a chic Marc Jacobs pantsuit. Expect a drastic change of sartorial pace when you watch the actress’s turn as a women’s rights activist in the historical drama, which opens in theaters on Friday. But, while her on-screen outfits are decidedly more subdued, the story behind the costumes makes them just as exciting. Mulligan stars as Maud Watts, a poor London laundromat worker who joins a group of female “footsoldiers” in 1912, bravely on the front lines of the British suffrage movement. Directed by Sarah Gavron, the film fuses fictional characters, like Watts, alongside real-life suffragette leaders such as Emmeline Pankhurst, played by Meryl Streep. The result is an eye-opening, emotional look into a revolution that’s rarely depicted in popular culture.

When it came to dressing an entire army of suffragettes, the film’s costume designer Jane Petrie clearly had her work cut out for her. Petrie’s strategy for depicting this historical movement through clothes? Go straight to the source, of course. She studied 19th and 20th century photographs and texts, then used as many authentic clothing items as possible — even though they required multiple repairs throughout filming, since 100-year-old pieces often fall apart. Before you see the amazing (and accurate) costumes onscreen, read our interview with Petrie, where we discuss collaborating with Mulligan and Streep, the importance of trusting your instincts, and finding inspiration in life’s most ordinary moments.

Read the interview on Fashionista.com