Sisters Marie and Karen Potesta of Micaela Greg first learned to sew and crochet from their Italian grandmother (herself a former designer), creating piles of potholders as children. The Detroit-raised, San Francisco–based pair initially split off for college — Marie studied fine art while Karen focused on engineering — but both went back to school to pursue fashion after graduating. This fall, they launched their co-designed knitwear line, Micaela Greg, creating an edited collection of intricate, op-art-influenced clothes that combine Karen’s skill in pattern-making and Marie’s eye for draping. “We had just gotten back from a trip to Tokyo, where we found tons of inspiration in origami,” says Marie. “We were also listening to a lot of David Bowie and looking at his black-and-white samurai costumes by Kansai Yamamoto. It was kind of sensory overload.” Their premier collection won the Avant Garde Gen Arts International Styles Award, showcasing a lineup of graphic leggings, twisted, sculptural tops, and standout trapeze skirts and cardigans. The clothing is produced entirely in California, made of merino wool and cashmere from luxe Italian yarn companies Loro Piana and Zegna Baruffa. Though the sibling co-designers inevitably run into disagreements, the pair says they ultimately complement each other’s strengths. “There are a lot of tears,” Marie says, laughing, “but there’s no one else I could do it with. Karen’s followed me everywhere we’ve ever gone. Our husbands have been best friends since they were 12. It’s a little bit like a really bad sitcom pilot.” The collection is available at Debut New York or online at SupermarketHQ.com. Click ahead to check out their designs.