"Bonnie Cashin was on our minds for pre-fall," Preen's Justin Thornton said in London, referring to the sportswear pioneer. "We wanted a very fifties look of American ease—languid with minimal fabrics." A cherry red suit with wide-leg trousers and a boxy jacket had a retro feel, like something Cashin fans Marlene Dietrich and Gloria Vanderbilt would've worn in the designer's heyday. Ditto a boxy wool crepe mushroom dress with striping details on voluminous sleeves. Given Michelle Obama's recent discovery of vintage, a precisely tailored sheath dress with elaborate beading (and a more modern vibe) may just prove to be the collection's secret weapon.

Cashin was known for her nomadic tendencies, and Thornton and his partner, Thea Breggazi, picked up on that by flipping through piles of National Geographic magazines and photographing hundreds of patterned carpets. A red and black ikat print turned up as an easy shirtdress, as well as on the bodice of a tailored wool frock. And let's not forget the label's Power Dress, made famous by Gwyneth et al.: They could've left it untouched; it is, after all, their top seller. But Thornton and Bregazzi aren't the types to trade on past glory. Their pre-fall version comes with a flamenco-esque ruffle detail on the bottom. We're guessing the peripatetic Cashin would have approved.