“It is the material that defines haute couture,” Yves Saint Laurent once said. “We whisper our secrets to each other: the refinements and knowledge of the cut.” The legendary couturier’s intuitive understanding of textiles—structured taffeta, draping velvet, and airy muslin—was paramount to his creative process. Inspired by beauty as diverse as the plays of William Shakespeare and the vivid colors of Moroccan architecture, Saint Laurent partnered with Lyon’s most inventive textile manufacturers, their expertise breathing life into his designs. With 30 ensembles on display, the celebrated couture-house-turned-museum offers visitors a glimpse into the collaboration between genius designer and master craftsmen. —Kausaur Fahimuddin