Ten years ago, Joan Shepp single-handedly redefined how Philadelphians think about style. A decade later, her Walnut Street boutique stands as a model for luxury retailers.

Shepp is often described in the same terms that are used to describe the coveted goods she sells: eccentric, brilliant and desperately chic. While luxury often connotes big names and bigger logos, Shepp’s taste tends toward the avant garde.

The Belgians (Ann Demeulemeester, Dries van Noten, Martin Margiela) and the Japanese (Comme des Garçons, Rick Owens, Junya Watanabe) get top billing and hang alongside Marni and Jean Paul Gaultier. And though she certainly stocks expensive names like Balenciaga and Yves Saint Laurent, she also mixes in trendy items with lower price points, like jewelry by Philadelphia’s own John Wind.

The store itself is a sight to see — it is as raw as it is polished. The cement floor is painted black, though some parts are left bare and embedded with pebbles. Oriental rugs cover certain areas, enabling the warehouse space to be separated into sections. Clothes hang on black wooden hangers with the white “Joan Shepp” label on silver industrial racks. This past summer, Shepp transformed the second floor into an in-store boutique for Y-3, Yohji Yamamoto’s collaboration with Adidas.

Not only is Joan Shepp unparalleled in its selection, the service is second to none. Dressed in black from head to toe, the sales team is knowledgeable, helpful and, yes, quite chic. Unlike the sales staffs at most high-end retailers, Joan Shepp employees don’t make individual commissions; rather, they receive team bonuses, a policy that allows for cooperation among the staff and communication with the customers.

Ultimately, Joan Shepp is the kind of store where an 18-year-old and an 80-year-old can buy the same thing ­— the difference comes down to styling. The Joan Shepp customer isn’t afraid to mix the high and the low, the European and the Asian, the playful and the serious. After all, a little dose of style goes a long way.

Joan Shepp

1616 Walnut St.

(215) 735-2666

The Goods: Comme des Garcons, Martin Margiela, Y-3

The Bottom Line: Impossibly cool clothes in an impossibly cool setting.