For decades, skiers and snowboarders have seen the techiest, most highly engineered synthetic fabrics as the pinnacle of alpine function and fashion—a sentiment held with particular vehemence by the hordes of snowsports enthusiasts who stream out of the Bay Area each weekend for places like Palisades Tahoe and Heavenly.

These days, though, one of the hotter items on the slopes is the traditional knitted wool ski sweater. The humble and venerable garment is “the greatest piece of ski equipment ever made,” said Louis Joseph, who runs Alps & Meters, one of the new e-commerce brands that have arisen to fill this demand.

Kevin Luzak, founder of Cache Seven, a social network startup for outdoor enthusiasts and guides, has a closet full of wool ski sweaters and has been an evangelist for them for years. “People used to give me a hard time about it—but it’s breathable, always comfortable, and getting away from the ecology of manmade fibers is just better for the world,” said Luzak. “It may be pure fashion to some, but wool performs great, and I love seeing all these sweaters out there again,” he said.