Day in the Life: Mona Kowalska

Mona Kowalska’s studio sits right below her shop on Mulberry Street, an area within walking distance of some of the coolest independent brands in New York City—Noah, Creatures of Comfort, No.6—and far enough away from the hustle and bustle of the chain-store fashion purgatory of SoHo for her to catch a glimpse of tranquility. When I meet her, the designer is in the middle of creating patterns for A Détacher’s next collection (she makes all of her own prints too), figuring out the right draping for a shirt she plans to include. “This was many, many muslins,” she says, showing me the most recent iteration.

Hanging on racks alongside the walls of her studio are the patterns from her past 20 collections—massive pieces of eggshell-white paper with intricate blue or black mark...