“Of course I stayed up!” beams New York designer Mia Vesper over the phone. Her all-nighter is thanks to Beyoncé’s new visual album Black is King, which was released on Disney+ at 3 a.m. today. Vesper had a special reason to burn the midnight oil: She designed a custom ensemble for Beyoncé and 60 additional looks for dancers and actors in the film.

Featured around 44 minutes into the visual album on a track with Pharrell, Vesper’s outfit is a shimmering Impressionist gown with bias draping and ruching and a dramatic headpiece. “Zerina Akers, Beyoncé’s stylist, said she wanted something that was iconic. When I think of Beyoncé, I always think of a cape or a headpiece, so I started there,” Vesper says. “There were about 20 different headpieces we made. I was putting traffic cones on my head and draping fabric across them and putting shoeboxes, and putting planters on my head. It grew from there.”

The gown represents a step forward for Vesper too. The designer, who started out upcycling vintage tapestries into jackets and shorts in 2017, has been slowly and sustainably growing her business with a made-in-New-York ready-to-wear collection of sporty separates and flirty minidresses. Making something on this scale was a first. “I was thinking, How to make a gown? How to make a gown?” she says of her early sketches of the dress. “I ended up draping a bunch of dresses all on myself and sending Zerina selfies. She picked her favorite one. I always let the textile tell me what it wants to do and then I kind of work from there.”

The textile in question is a Monet-inspired Rayon Lurex plissé material from Russia. Vesper typically prefers to use vintage or deadstock materials to cut down on waste, but she keeps an eye on special new fabrics being made in Russia, a market typically ignored by other American fashion brands. “If I’m working with a new material, it has to check off the box that says, ‘This fabric deserves its place in the world.’ This one just screamed that it had to,” she says. “I ordered thousands of yards immediately, which I never do, but I had a feeling about it. Thankfully I did because here we are!”

Beyoncé’s look came to be after Akers saw Vesper’s work in a Los Angeles showroom last year—but the story doesn’t end with the film’s release. Once Vesper got word that the look would debut in Black is King, she took some of her remaining fabric and began to cut a version that is going on sale for preorder on her website today today. “I wanted to make something that was as beautiful as the dress I made for Beyoncé but that was also wearable and affordable. I made the dress in a night and sewed it all up,” she says of the $395 piece. “I think it’s flattering for all women, it’s such a body-conscious, form-flattering silhouette.”

Her look might just be one in a sea of unforgettable ensembles that Akers and Beyoncé created for this incredible album, but it’s inclusion will live long in Vesper’s heart. “When you think about a celebrity endorsing your work, you really can’t think of anyone better in the universe than Beyoncé.”