Olivier Rousteing barely knew the ’80s, that era provides a never-ending wellspring of inspiration in all its padded-shouldered, glittery, maximalist excess for the Balmain Pre-Fall 2020 collection while also lift several cues directly from the playbook of the ’50s and ’60s.

Since next year marks the house’s 75th anniversary and paisley, for example, was one of Mr. Balmain’s favorite motifs, Rousteing yanked it into the present on ethereal long dresses with wide, gathered waists, on a fully embroidered bodycon dress in Pop colors, and winningly on a dévoré blouse paired with ultra-high-waisted flared trousers. “Paisley may be about French-granny nostalgia, but it’s all in how you use it,” the designer said, calling the richness of the house archives his “Proustian madeleine.”

Rousteing made a broad case for trans-seasonal dressing, sweeping from a mint lace blouse with a charmeuse jabot and trailing sleeves to crisp houndstooth suiting, a tweed-tartan bomber, and dramatic capes, one of them a reiteration in leather of the house’s hit B Bag. While hewing to house codes—a pullover means tulle with crystal, beads, and sequins, for example—the overall feel was gentler, more romantic, and not quite as bodycon, but without going so far as to alienate a base that likes dressing short and tight.

Rousteing says he is working on “real awareness,” brushing up and staffing up to align his designs with clean materials and sustainable production. “That’s not a trend,” he said. “It’s the real world, and once you change your mind, there’s no going back. It’s way beyond clothes.”