Sustainable style considers the environmental, social and health affect of the design, manufacture and disposal of clothing, footwear and accessories, with the purpose to minimise any adversarial effects of the trade. Finding La Marelle is half the fun. It’s in the 2nd arrondissement near the tree-lined alleys of Palais Royal, inside Galerie Vivienne, a Belle Époque, glass-roofed, coated passageway with preserved mosaic floors, half-moon windows and moldings of goddesses and nymphs. On the bottom flooring are inexpensive French manufacturers like Sandro and Isabel Marant. Upstairs is the place issues get fascinating. There may be a whole wall devoted to Japanese design, a section of made-in-Paris furs, a rack of designer denim and effectively-priced prepared-to-put on.