JEAN-FRANÇOIS LESAGE grew up among the gold threads and glass beads of the House of Lesage, France's most revered embroidery workshop. His father, François Lesage, had made it a symbol of the highest craftsmanship in fashion, producing haute couture embellishments for houses such as Chanel, Lanvin, Balmain, Givenchy and Christian Lacroix.

At 7:30 every morning, before Jean-François headed off to school, the petites mains, artisans known for their fine handwork, would stop by the family home in Chaville, a leafy suburb of...