A New Ultralight, Ultrabreathable Waterproof Membrane


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Next spring, when you go to replace your favorite lightweight running jacket, biking shell or rainwear, there'll be a new waterproof breathable on the racks.

eVent's DVL (short for Direct Venting Lite), incorporates a new membrane, pictured above, that is light and breathable and allows an imperceptible amount of air to pass through to clear the sweat out from inside your jacket fast.

Engineers at eVent have figured out a way to print directly on the surface of the membrane so that now you don’t need 2.5 or three layers to make a complete jacket. More material makes a jacket heavier and hotter. A typical waterproof breathable has two layers of fabric that sandwich a membrane and protect it, or a layer of fabric, a layer of membrane, and a polyurethane coating on top. 

“eVent DVL waterproof fabric stands alone in this class of fabrics because it does not use a polyurethane coating to protect the membrane from contamination,” explained Glen Crowther, product line leader for eVent fabric. “Polyurethane, applied as a coating, clogs the pores of the membrane and impedes airflow. In eVent fabrics, the individual fibrils forming the membrane are treated so the pores remain open—or air permeable—and heat and moisture can pass through directly.”

eVent's new proprietary membrane uses the same base as traditional eVent and Gore-Tex, ePTFE (scientific name: expanded polytetrafluoroethylene), which allows moisture to escape, but keeps out the wind and rain. 

“eVent DVL fills the market’s continuing demand for light waterproof breathable fabrics,” Crowther said. “eVent DVL waterproof fabric uniquely offers the ultimate combination in rainwear: it’s air permeable, breathable and 100-percent waterproof. We believe it is best in class by all three measures for activities and seasons that call for lightweight, packable rainwear.”

Rab is one of the first companies to use the new membrane. It will show its new Viper Jacket, designed for alpine climbing, at the Outdoor Retailer Show in Salt Lake City in August. The Viper has a helmet-compatible hood, two A-line chest pockets and a napoleon pocket—all harness and pack compatible—and pit zips for extra ventilation, all for under 14 ounces (men's large).

“DVL fabric is unique in that it offers the reliable breathability and durability found in other eVent fabrics in a much lighter fabric more specifically designed for warmer-weather adventures,” said Samantha Kilgore, marketing manager for Rab USA. “Rab’s mission here is to create the only truly comfortable summer rainwear on the market, where dampness against the skin is not an issue.”

Rab Viper, $260; available February 2013;

—Berne Broudy

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