See sketches and get the insider info on the much-anticipated movie
Credit: Charlie Gray

With lead actors as attractive as Marion Cotillard and Brad Pitt, Allied costume designer Joanna Johnston says “you could put them in a brown paper bag and they would look amazing.”

But when it came time to design their costumes for the new WWII spy thriller Allied, Johnston tells PEOPLE she was inspired by the classics. “The inspiration really was old-fashioned Hollywood — films were slightly lifted during that time. There was quite a glamour aspect to it, rather than it being sort of war-torn.”

The film itself owes more to classics like Casablanca and The Maltese Falcon than it does the gritty realism of Pitt’s past WWII period pieces like 2014’s Fury. “I just thought,[Pitt and Cotillard are] both so beautiful – what would be the point in making them look sort of threadbare? It’d be a bit sad,” adds Johnston. Instead, the costume designer relied on old glamour shots for inspiration.

Below, Johnston takes PEOPLE through some of her favorite looks from the film:

Credit: Daniel Smith
Credit: Illustration by Jacqueline Bissett

“This is Max in the desert. I like this idea that he had a turban, and it was a little bit of a nod to The English Patient with Ralph Fiennes — I just thought it was such a nice look. And then these amazing glasses that are really cool.”

“With the props department, we designed this great kind of rucksack, and I thought this asymmetry was good because it looked like a bandolier-style. The boots we had made from a company that actually made boots at the time called Trickers in London, so that was super cool. The blue [in the turban] was really just to break up the outfit — and also Brad’s got really beautiful eyes, so there was just a lift there.”

Credit: Daniel Smith
Credit: Illustration by Jacqueline Bissett

“This is the first morning they’re together. This dress is actually based on a French fashion plate I found. I wanted this diagonal check design, and this whole skirt is cut in one, so the printers printed on part of the dress and the rest is left plain. It’s kind of shirt-dress, so it’s casual but chic. I liked the box pleats because when she’s walking it’s a very pretty, elegant movement, and when she sits it falls so nicely.”

“The skirt color is a nod towards the Air Force blue that [Pitt] wears later in the movie. I originally designed her hat in blue as well, but we went to a natural straw; it was prettier and it was more appropriate for the scene once we got closer to it.”

“As for Brad, this is the second pale suit he wears in the film. It’s a very, very lightweight tropical — what they call a nailhead tropical wear — suit from London’s Holland & Sherry. We made it a three-piece, single breasted jacket. The same suit is used to go with a double-breasted jacket when he goes to the German embassy. It’s four pieces that work in two different ways with two different jackets.”

Credit: Daniel Smith
Credit: Daniel Smith

“This dress is a column shape, which means it’s narrow and long. She has to run [in this scene], so I added some fullness in the skirt to give her room to move. I also made it structured underneath, but the fabric is very fluid. It becomes very liquid, particularly outside, which gives it that watery feel I wanted. It’s a combination of the color and the fabric.”

“Then his suit is a simple ’40s style, very classic masculine influence from the time, [like] Cary Grant … Just super elegant and super clean. He also looks absolutely brilliant with just a shirt and his pants, these beautiful high-rise pants and suspenders. It was actually Pitt’s idea on the outset that we keep the jacket off initially, and he was right.”

Allied hits theaters Nov. 23. Are you excited to see the costumes?