NW Alpine Eyebright Jacket: Burly and ultralight

In a world of waterproof/breathable shell jackets, the NW Alpine Eyebright ultralight jacket is unique. I don’t recall coming across anything else quite like it during my former life of peddling similar products for outdoor retail stores and used-gear shops.

It’s remarkable what is being made with Dyneema these days. Weight for weight, Dyneema is 15 times stronger than steel and light enough to float on water, and it comes in several forms: fiber, unidirectional sheets, fabrics and tape.

The Eyebright’s Dyneema construction makes it incredibly light (4.5 ounces), durable and waterproof as well as breathable. The material is puncture- and tear-resistant. The only stitches are for the zippers–all the other seams are taped and fused. Fewer stitches mean fewer holes in the garment, which translate to greater water resistance. Sounds like the perfect shell jacket, right? Maybe. It depends on how often and what duration you’re using it, but I’ll get to that.

The material has a bit of elasticity, which surprised me because I’ve generally thought of Dyneema as a static (non-stretchy) element. The makeup of the jacket is listed on NW Alpine’s website as “15 percent Dyneema, 40 percent ePTFE and 40 percent other polymers.” What does that mean? I asked Bill Amos, the founder of NW Alpine, to explain.

“It can help to think of Dyneema as a fiber that reinforces other materials,” he said. “The Eyebright fabric is three layers: the inner layer is the eVent PTFE membrane [which allows for waterproof-breathability], the Dyneema fibers are in the middle, and the face is the polyester and ‘other polymers’ portion…. [About] the Dyneema content, basically the idea is to use the least amount of fiber to do the job while being twice the strength of anything else in the same weight bracket.”

I also asked Amos to give me more details about the Eyebright’s construction.

“Typically waterproof/breathable jackets are either sewn and then seam-taped with a hot air seam-taping machine; or they’re fully bonded using adhesives and a heat press; or they’re welded with an ultrasonic machine that uses ultrasonic frequencies to heat and bond the materials,” Amos said. “Dyneema fibers have a low melt temperature relative to other fibers (around 270 F), so applying temps greater than 270 melts the fibers, which obviously isn’t a good thing. As long as you can keep the temps below 270 you’re OK to use heat…. The Eyebright is laser cut (because raw edges are visible at the seams, and it’s cleaner/easier than cutting with a knife) and then bonded together using pressure-sensitive adhesives that don’t require heat to cure. The whole process is very time consuming and is all done by hand.”

The high-tech components and hand construction (made in the USA), explains the price, which is more than three times the cost of at least one ultralight shell that I’ve found to be comparable in performance for my typical needs–Outdoor Research’s Helium II. In terms of durability, however, the Eyebright is likely going to hold up much longer.

If I were thrashing through the Alaska bush under the grey, dripping skies of the monsoon season, the Eyebright would be a great option. Its toughness could withstand the constant abuse of scratching willow branches and it would be light and breathable enough to keep me drier for longer during such vigorous activity, venting the sweat and keeping out the cold wetness.

The Western Slope of Colorado where I live is a dry climate. Nothing like Alaska or the Pacific Northwest. When I rack up for a long day of climbing, I bring a shell jacket as an insurance policy, not an eventuality. And when it does rain, the storms are usually short-lived. More often, I wear the shell to protect me from the wind.

This means I want a jacket to pack down to almost nothing and stay out of the way because I need it so rarely. For this reason, a feature I really like about the Helium II is that it stuffs into a self-contained pouch that has a clip loop, allowing it to ride on my harness–perfect for climbs that are short enough not to lug a backpack but long enough that it’s nice to have something to keep me warmer at the belays. The current Eyebright design does not include this pouch/clip-loop feature.

Amos said there are a few reasons why.

“To be honest we haven’t figured out how to make it work and be robust enough with the way it’s constructed,” he said. “It would really suck to clip it to your harness then snag it on a rock or something and have the loop break and there goes your expensive shell. Also, the pocket zip would have to be both coated for water resistance and have a double slider (front and back to accommodate closing it when it’s stuffed). The other aspect is that while it’s OK to stuff, it’s better for the longevity of the jacket to lightly fold it and smooth the air out (obviously this rarely happens in the field). We’ll continue experimenting with it, though, and hopefully be able to add it as a feature in the future, but we’re not willing to put it out there until it’s right.”

On the flip side, I appreciated the bomber quality of the Eyebright’s Dyneema construction while scootching up a dirty chimney and stuffing my arms into sharp, rotten cracks on the horrendous, towering stack of choss that is the Grizzly Creek Wall in Glenwood Canyon, Colorado. With other jackets I’ve been more concerned about ripping a seam in the sleeve, or even just fraying some threads in the stitches. It’s nice to know that the Eyebright is made to handle this abuse in moments when I might otherwise hesitate.

As for waterproofness, my feeling is that the Eyebright would hold out much longer in a prolonged rainstorm than my nylon shell, which has several stitched seams. If my Helium II was fresh off the store rack it might hold up through a day of solid rain well enough, but if I wore it regularly in those conditions, season after season, I have no doubt that the Eyebright would be faring much better through similar use.

So, if you need a bomber ultralight shell that you plan to use often for long durations and if you can afford it, you might feel that the price is justified. But considering the cost, the Dyneema fabric’s vulnerability to heat compared to nylon, which melts at around 500 degrees–it seems like this could make a slight difference when it comes to things like campfire sparks–and the jacket being a tad less portable and bulkier to pack, it’s not going to be the perfect ultralight shell for everyone.

Derek Franz is the digital editor for Alpinist and has been weathering storms on high rocks for about as long as he can remember.

Pros
Very durable because of Dyneema construction
Light (4.5 ounces)
No sewn seams (except for two zippers) allows greater water resistance
Made in USA

Cons
Expensive
Doesn’t stuff into a self-contained pocket
More susceptible to being damaged by heat than nylon