Throughout history, fabric has been one of the most expensive and treasured of luxuries. Still-viable textiles from well-worn clothing were often reused to make a child’s garment. And a richly embroidered gown might be taken apart and repurposed as a curtain or wall hanging. Boro, the Japanese word for “rags” or “tatters,” is also the name for a patchwork textile that peasants pieced together in the 19th and 20th centuries, when cotton was not easily obtained in Japan. Not only does the practice embody the Japanese aesthetic of elegant imperfection, the resulting garments are ravishing creations of matter-of-fact modernism. Fifty archival pieces are on view here, alongside boro-influenced avant-garde designs by Rei Kawakubo, Issey Miyake, and Yohji Yamamoto. —L.J.