The story behind those Mamma Mia! Here We Go Again overalls

It’s been 10 long years since the original Mamma Mia! first hit theaters, but the prequel/sequel’s timing is truly impeccable, if only for one crucial reason: Overalls are in again!

Meryl Streep’s signature look from the 2008 film gets an origin story of its own in Mamma Mia! Here We Go Again, which stars Lily James as the younger version of Streep’s Donna during the summer when she became pregnant — by one of three different possible fathers — with her daughter Sophie (Amanda Seyfried).

“It ended up being a look that defined her,” Streep says in an exclusive featurette, above, about Donna’s original overalls. They become all the more symbolic in the new movie, which chronicles such a formative episode in her life. “It’s really key in the story that we see her start off her journey, and then we see when she actually becomes the person who wears the dungarees,” the film’s costume designer Michele Clapton tells EW. “I really liked the chance to do that, and to sort of say when she crossed over from being the girl at Oxford [to being] the girl on the island.”

Tasked with crafting a single garment that would be doing that much heavy lifting, character-wise, Clapton had her work cut out for her. “We sort of wanted to have a feel of [Streep’s pair], so that it linked through to Lily,” she says. In capturing the spirit of the original but finding the perfect silhouette for a new actress, “we made them full-length, we made them cutoff… we made so many different shapes and lengths. But actually, in the end, we went for them really pretty similar to Meryl’s.”

But fidelity to the spirit of the character wasn’t the only consideration. “It was really important, because there’s so much dancing and movement, that they stretch,” she says. “It was tough to find [a fabric] that had the stretch but didn’t look like it had the stretch, and we liked it to have some sort of surface texture, because it looks so much more interesting. We went through so many, and we went through so many different shades. We were dyeing it, like, weeks, just trying to get the right shade.”

There’s also the issue of overalls being, you know, pretty shapeless much of the time. “If dungarees aren’t cut right, they just can really not make bodies look good, so it was very much a case of sort of cutting them, shaping them into the back,” Clapton says of the deceptively tricky style. “They either have to fit in every dimension or not fit at all. Some people look great in really baggy, sort of men’s-type dungarees, but for Lily and Meryl, I think it was nice that they sort of fitted their body better.”

Once Clapton and her team went through dozens of incarnations of overalls (“my cutter probably says 100, but I don’t think it’s that much,” she says) and settled on a cut, length, weight, stretch, and color, they constructed three or four pairs for James (one of which was slightly roomier to accommodate Donna’s pregnancy), and remade one pair of the originals, “just so they looked fresher,” for Streep. “It’s so many different aspects, I don’t think people even realize,” Clapton says. “It’s like, ‘It’s just a pair of dungarees, get over it.’ But actually it’s really complicated to make them do everything they need to do and look good.”

All the work paid off when James got into costume. “I put them on and I went, ‘Oh, yeah, I feel like Donna,’” the actress says in the featurette. The garment’s first appearance, teased in the video, is “quite a defining moment,” Clapton says. “It says quite a lot about her.” So what does this particular piece of denim communicate about its wearer?

“That she’ll have a go, that she’s sort of quite feisty, and she’s sort of not scared to muck in,” Clapton says. “She has fun. And also, because of what she goes through — the three fathers and all that — it’s quite nice to have a really practical person as well. It would have been wrong [to have her] in pretty dresses all the time.”

“It’s part kid and part worker and part fun,” Streep sums up the look in the featurette. “There’s nothing that outfit won’t do.” My, my, how can we resist it?

Check out the exclusive featurette above. Mamma Mia! Here We Go Again hits theaters July 20.