Kaia Gerber has a Re/Done T-shirt in her closet that she got about 10 years ago and still slips on regularly. “I wear it all the time, and it just gets better and better,” says the 24-year-old model, actress, and Vogue September cover star , citing its worn-in, buttery feel. “That’s a testament to it being, truly, the only thing you could ever need in your life.”

Born and raised in California, Gerber deems T-shirts and jeans the most essential part of her wardrobe. “I was always like, ‘You just need a good pair of Levi’s shorts and a white T-shirt, and that’s all.’ And then when Re/Done came out, I was like, ‘Oh my God, this is everything I say you need—and the best version of it.’”

This isn’t just lip service; Gerber is so dedicated to the brand—which has developed a cult following amongst LA cool-girl types (and those who aspire to look like them)—that she signed on as an investor, creative partner, and advisory board member earlier this year . Next week, the brand launches Kaia Vol. 1, a 60-piece collection that serves as the manifestation of that partnership.

“What I have always loved about Re/Done is that even as it’s grown, you never feel like you’re losing the personal, intimate experience of shopping there—which, to me, is a large part of the appeal.” At this point in her life, Gerber adds, she’s “been the face of things, but I’m ready to be more hands-on and creatively involved. And then I met Meredith, and I was like, I don’t care what I have to do, I need to work with this person.”

Meredith is Meredith Kahn, Re/Done’s head of design, who signed on just over a year ago. One of her first tasks was working with Gerber on the collection, but the two discovered they had something of a hive mind, sharing references that were eerily aligned and going on vintage-shopping trips for inspiration (let it be known that Gerber is a Pinterest super-user, with some 40-plus inspiration boards—complete with elaborate names—going at any given time).

“We have the same sensibilities,” Kahn says.