The gap between high-end and fast fashion is getting wider, and the “contemporary” space in the middle can be less than inspiring. But Derek Lam’s little sister label, Derek Lam 10 Crosby, is a highlight of that in-between market. Named after the location of his first store and headquarters, the line is inspired by the cool, downtown New York girls the designer spots in the neighborhood. While other diffusion links might simply water down a runway trend, 10 Crosby is as considered and luxurious as Lam’s main line. “We’re always elevating,” he said. “It’s key to elevate the experience, the product, and the message.”