Waterproof shells for spring and summer have become a lot more breathable thanks to a recent arms race between companies over advanced shell fabrics. We’ve been testing the $140 Mountain Hardwear Plasmic jacket, for instance, after it came out in March. The coat uses the proprietary Dry.Q waterproof-breathable fabric on the outside, an ePTFE material in the same category as Gore-Tex. Inside, near your skin, is a layer called EVAP which is designed to wick moisture toward the outer membrane. EVAP has a structure that increases surface area to draw water away faster, according to the company. And yet, even with the waterproof shell and sweat-removal technology, the coat is light at 10.2 ounces.
Our first order of business was testing the Plasmic’s basic waterproofness. We spent an hour in heavy April rains searching the mulchy forest floor for new spring flower shoots. Leaning down, looking up, climbing trees, we didn’t get a drop of water inside the coat the whole time. We even dunked head first under a stream.
To keep water out in a violent storm, the hood and neck can be independently cinched tight against your face and head, the waist hem has an elastic cord, and the cuffs tighten via velcro tabs. The jacket uses a flat injection-molded YKK zipper called an AquaGuard Vislon, a fastener released in 2010 that repels water without requiring a protective fabric flap over the front. YKK tests its zippers in its Tokyo R&D center by placing them under a shower flowing at exactly 3.9 inches per hour for five minutes then checking for leakage. (As zipper geeks, we felt we need to call YKK about this directly).
To test breathability, we ran hard in the jacket for 40 minutes on a trail with a 600-foot elevation gain. The inside certainly became hot and sweaty, but no more than a specialized cycling or running jacket. Our perspiration dissipated quickly. We were surprised, especially since the armpits and pockets are stitched closed (many companies vent waterproof-breathable shells in these places so that fabric doesn’t have to do all the work.) The coat itself is a lot bulkier than a running shell, but it does have the built-in waterproofing.
For a $140 jacket, the Plasmic performed exceptionally well. About the only thing we didn’t like was the billowy fit around the trunk. The extra space would certainly accommodate a midlayer for cold weather, but the coat didn’t have the tailored profile for streamlined hiking through the woods. But for rummaging around in mud and leaves, there’s nothing better.
The Plasmic comes in five sizes from small to 2X-large in nine colors.