It's rare for a secondary line to establish its own identity as distinctly as Marc by Marc Jacobs. Now going into its fourth season, the ultratrendy label has won the hearts of Jacobs' collection customers, not to mention the retailers who've watched his creased jeans and striped sweaters fly off their shelves. Even better, Marc has become a cult brand among fashion-savvy (is there any other kind?) high school girls.

For Fall, the designer remained true to his favorite decade, the '70s. A master of the artfully mismatched, Jacobs assembled deceptively simple, layered looks in those odd '70s color combos like blue/rust and brown/purple. (He even worked in a floral thermal shirt, putting it under a short-sleeve turtleneck.) As always there was plenty of denim, although corduroy and velvet also made their presence felt in jackets, skirts and flare-leg jeans; these had a line artfully bleached out around the hem, so they looked like they'd been shortened and then let down. Rounding out the collection were knee-length skirts, close-fitting blazers, baseball jackets, zip-front cardigans, great three-quarter coats and rainbow-striped sweaters, all accessorized with long knit fringed scarves.

Worn all together on the runway, the line looked fantastic. And real-world customers who limit themselves to individual pieces—there is, otherwise, a slight risk of being mistaken for Marcia Brady—are sure to be happy.