When Stella McCartney showed her Resort 2013 collection last month, she made sure her models were wearing their Sunday best—Sunday Riley, that is.

Joining the ranks of Acne, Helmut Lang and The Row, the British designer turned to Sunday—whose products are sold exclusively at Barneys New York—to ensure that her models looked luminous (despite the gray skies that hovered overhead that day). Below, Sunday fills us in on the look she created for Stella and some best-kept backstage secrets.

Barneys New York: What was the inspiration for the Stella McCartney beauty look?

Sunday Riley: Stella McCartney asked us for three things: gorgeous, radiant skin, look-at-me eyes and fresh, summery-rose lips and cheeks. The inspiration for the show was a fresh-faced city girl with a bit of an edge—the girl with a makeup look that makes her unique, whether it’s a bright lipstick she wears all the time, a beauty mark or, in this case, a striking eye. We used our (soon to launch!) Velvet Gel Eye Pencil in Pitch Black, cheek color in Blushing for flushed radiance and our sell-out shade of lip color, Marie Antoinette, for a subtle dusty rose lip hue. The finished effect was “downtown chic,” which complimented the floral patterns, brocades and leopard prints from the collection.

BNY: How do you prep the models’ skin before putting on makeup?

SR: We always begin with Good Genes to brighten each model’s complexion and improve texture. Once that has been absorbed into the skin, we follow with our Effortless Face trio: We smooth on our Effortless Breathable Tinted Primer, follow with Liquid Light Breathable Perfecting Foundation, and then pat Juno Transformative Lipid Serum onto the skin. It’s a technique that we developed at New York fashion week a few seasons ago and has since become a backstage staple at all of the shows we have sponsored, including The Row, Lanvin and Helmut Lang. Each product is very lightweight so it’s a great combination for summer.

BNY: Did you use any products on the body?

SR: We use Juno Body Serum on arms, legs and decolleté for luminous, silky skin. Many of the girls come from other shows, so it’s a great product to renew skin for a glow that looks amazing in photos.