Product test

It's worth looking at the details of this Black Diamond jacket

4.11.2020

The Black Diamond Highline Stretch Shell should stay waterproof without you having to refresh its coating. This is due to an environmentally-friendly process, not aggressive chemicals.

Before I get to the Black Diamond garment, there are a few things to address: a new outdoor jacket is always great. You remove at least five different labels that promise perfect properties and leave you feeling completely protected. Any water simply runs off. But a few months later, you're left out in the rain – quite literally. The very same jacket hangs off you like a wet sack and you no longer know whether it's sweat from inside or water from outside that's making your clothes stick to you. The DWR has worn off. DWR stands for «durable water repellency». This layer keeps water away from the skin. But if it absorbs it, the jacket is neither waterproof nor breathable. What you can do is wash it and waterproof it again. The manufacturer will have care instructions depending on the type of coating.

You should take note of everything in your jacket when you buy it. In recent years, outdoors companies have discovered sustainability. This is good, and it makes sense. And I accept that everyone in the industry cares about the environment. However, there's a conflict here that's difficult to resolve: when we get out into nature, we mostly tog up in synthetic layers that protect us from the wind and weather. This means chemicals. Primarily PFCs, which are damaging to both the environment and our health and a method of choice to give materials water and dirt-repellent properties.

There are now alternatives as far as waterproofing is concerned. Walking through the halls of the world's largest industry trade fair [ISPO](in German)(https://www.galaxus.ch/de/page/nachhaltigkeit-ohne-ende-das-war-die-ispo-2020-15200) in Munich, you get the impression that plastics and chemicals are history. Everyone is advertising with sustainability front and centre, of course. We tend to overuse the word here at Galaxus too. And obviously the innovations are often only partial aspects of the material and its manufacture. But they are steps in the right direction. And some of them are award-winning.

In 2019, the Black Diamond Highline Stretch Shell won the «Outstanding Outdoor Award» in the «Rain Apparel» category and was designated 2020's «Gear of the year» by Outside Magazine. Let's find out why.

The jacket

The Highline Stretch Shell is a three-layer jacket which draws on the proven Black Diamond concept. Its straight cut and elastic nylon offer a high degree of freedom of movement, which you'll appreciate when hiking, mountaineering or climbing. It doesn't actually have the plastic feel of some rain jackets, even though it's much thicker and heavier at around 360 grams.

A chest pocket, two side pockets, zips protected against moisture, underarm ventilation and a helmet-compatible hood are basic requirements in this category. The stitching is fully seam taped, which benefits the water resistance. It has a water column of 20,000 mm. Values and standards like these are always a bit abstract.

This means that you can be dry in the EU but not totally waterproof in Switzerland. Even trying to translate water columns into practice only provides vague details.

Ultimately, you don't care about standards when you're standing in the rain. First, second or third class makes no difference; you're either wet or you're dry. Whether you stay dry or not depends on water pressure, the condition of your jacket and details of how it's finished. If you have a rucksack with you, the coating has to withstand the friction and pressure on the bag's seams. If the zips aren't protected or the stitching is a weak point, moisture will penetrate regardless. If the DWR is no longer intact, the waterproof rating is meaningless.

On paper, the Highline Stretch Shell does everything right to be waterproof for the long term. In terms of breathability, it scores well at 20,000 g/m2/24 hours. The moisture vapor transmission rate measures how much water vapour evaporates through a square metre of material in 24 hours. It's an objective lab value that ultimately means nothing because life can't be standardised.

The jacket passed the toughest test that I've given it so far: when I [tested the X Speed Pedelec](in German)(/de/page/klever-in-koeln-das-s-pedelec-x-speed-pinion-im-test-17045), a big summer storm took me by surprise. Travelling 45 km/h on the highway in driving rain, I looked like a wet rag, but the protective layer held firm. And how this water resistance is achieved is really interesting.

The history of a coating

The innovation that this jacket has to thank for its awards comes from a company called Green Theme Technologies, GTT for short. The company has been operating since 2013, starting out with experiments in the kitchen of Dr. Gary Selwyn. Seven years ago, the experienced chemist was searching for a process to waterproof textiles without using damaging chemicals or wasting water. And he succeeded.

The trick: every fibre of the material is individually coated. To understand this, I have to go into detail. Monomers – reactive molecules – form polymer chains which encapsulate each fibre of the fabric and are permanently bonded with them. This makes the material waterproof and breathable. The initial solution uses no water, so not a single drop is wasted or contaminated. It's locked into the material under pressure before heat is applied for thermal curing. If the details interest you, you can read more about the process here.

The bottom line is an environmentally-friendly solution that not only competes with conventional PFC coatings but surpasses them. The result is smoother, more waterproof and more durable. With Dr. Gary Selwyn's EMPEL™ process, even wool can be waterproofed for the long term.

A virtually antique method is the most practical way to determine and compare properties like these: the Bundesmann water repellency test. The first reference to Dr. Bundesmann's test is in the 1935 work «Eine neue Apparatur zur Gebrauchswertprüfung wasserabstossend imprägnierter Textilien» (A new apparatus to test the usability of water repellent textiles).

The fact that it has lasted to today is down to the fact that the test setup is pretty practical. The different fabric samples are mounted over cups in a rain chamber. The underside of the fabric is rubbed by a wiper which is intended to simulate the movement of the wearer. The setup rotates and is designed so that the same amount of water falls onto all the cups. At the end of the process, the test determines how much water has penetrated the material and how much it has absorbed. And GTT's EMPEL™ process sweeps away the competition. Dr. Selwyn isn't the most gifted YouTuber, but he explains it on his channel.

Verdict

The Black Diamond Highline Stretch Shell has everything you need to be protected in extreme weather situations. And not at the expense of comfort. Its stretch material makes it really comfy to wear and doesn't reduce your mobility. The interior is pleasantly silky against the skin. On the outside, it's so sleek that I don't just like wearing it in the rain or up in the mountains.

But it's the GTT technology that turns a very good jacket into an award-winning one. An environmentally-friendly process with supreme performance – two factors that should please many outdoors enthusiasts.