Blown Away By Marmot's New Fabric
Here's the thing, I've never been overly keen on what are known as 2.5 - or two-and-a-half - layer fabrics. They're light, they can be very effective, but they've always been a bit of a budget choice and the way they're made with a printed pattern protecting the membrane from abrasion just doesn't feel as substantial as a 'proper' three-layer fabric and I don't expect them to breathe as well as top-end three-layer fabrics.
I am, I guess, slightly prejudiced against them. Until now...
At last month's ISPO trade show, Marmot introduced a fabric called Nano Pro Membrain. It's their own-brand 2.5-layer fabric and it scores big numbers in laboratory tests for vapour permeability. Like really big numbers.
All of which I took with a pinch of salt, because lab tests don't always tell you how something performs in the real world. So I listened and nodded and agreed that it sounded pretty impressive - the 'big number by the way, was 47,000g per sq metre over 24 hours, which is a vey big number. Bigger in fact than the other numbers.
Smaller Is Better?
And the guys at Marmot explained how the PU membrane had been carefully engineered so the pores were not only really regular, but also slightly smaller than before, which paradoxically meant that they breathed better, because it turned out there was no need to add more PU to protect them from oils and smut. Okay, I paraphrase here, but ultimately it doesn't really matter, what counts is not lab tests, or technology, it's simply how well the fabric and the garment works in the real world.
So when a few weeks after the show, a brand new for spring 2014 Marmot Artemis shell jacket showed up - see our first impressions - I was curious. First outing was tramp through central London on tube strike day followed by some light use on a bike. I was cautiously impressed, it just seemed to work albeit under not too strenuous conditions, some local walking in the Peak confirmed the impression.
Then last Sunday, faced with the sort of grey, drizzly murk that's dull for walking, but fine and fun for mountain biking, the Artemis got some proper hammer layered over a Brynje mesh baselayer. It was the sort of weather where waterproofs used as windproofs really suffer. Damp, but not really wet, cool, but not properly cold.
A Brutal Test Of Breathability
And mountain biking in the Peak, is a brutal test of breathability. Because you spend more time climbing than descending. Because the climbs are steep and tricky and drag you over threshold into the anaerobic, high heart rate, seat-generating, red-zone. And because you tend to move faster and work harder than you would when walking the same trail.
And I have to say, in terms of breathability, the Artemis absolutely rocked. I was comfortable from the off and I stayed that way despite not bothering with the venting pockets or pit-zips even on sustained climbs. I kept waiting for the awful, boil-in-the-bag explosion of heat and sauna-like steam inside my jacket and sweat pouring down my face and into my eyes, but it simply didn't happen. I just stayed comfortable.
Forget the design and the fact that it's not really aimed at mountain biking or running for that matter, the breathability of the fabric just felt outstanding. The only conventional waterproof fabric I've used that's at a similar level is Polartec's NeoShell and, as an alternative technology, Paramo's Nikwax Analogy fabrics, though they add insulation, which you don't always need.
That's not the same as saying the Artemis jacket is flawless - wait for the full review - but for sheer fabric performance, it does seem really impressive, on a par or better than many windproof materials I've used. Which for a fully waterproof fabric is quite a big deal.
The final test was getting home and stripping off the jacket. Underneath my baselayer was basically dry, a little moistness under the pack area, but otherwise fine. By contrast, a friend who'd been wearing a soft-shell was, well, let's say, not quite so dry and comfortable.
Okay, it's just one outing and there's more to a jacket than just fabric properties and - despite what anyone tells you - you can, if determined, overwhelm the breathability of anything when working hard, but I think it's fair to say that there's an interesting new contender on the breathability catwalk.
More Marmot stuff at www.marmot.eu.
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