(longtime) experience with dermizax

I don't have any first-hand experience with Dermizax, but I was interested in it as well, so I did some reading and made a lot of inquiries. The only Dermizax available at that time was the original product. I don't have any information about the newer and allegedly more breathable Dermizax MP.

You ask why Dermizax is not used in a larger number of garments. The answer is that the breathability is zero, and waterproofness is completely reliant on the DWR. The original Dermizax is a NON-POROUS membrane. There are no tiny holes in it at all. It moves a small amount of moisture out of the interior of a garment because it is hydrophilic and water can soak through the membrane at a slow rate. This means that water can just as readily soak in from the outside if the DWR is compromised. So, Goretex breathes poorly but stays waterproof if the DWR is compromised; the breathability of Dermizax is worse than Goretex, and it ceases to be waterproof (and even wicks water in from the outside) if the DWR fails.

This information is from users. I got a different story from garment manufacturers and retailers, of course.

I know that it works in a totally different way.
According to your describtion it wouldn't make sense to use it all. BUT why do some companies still use it and why didn't Erin and Hig complain about it on their long Alaskan trip?

KUIU uses Dermizax EV from Toray in their Chugach rain gear. It is tough stuff and breathes incredibly well. It is right at the top with eVent in terms of breathability. Its toughness comes from the four way stretch Primeflex fabric. Its nice not having your rain gear bind up when moving.

You can check it out here.

KUIU Chugach Jacket

Toray Dermizax EV

I have no idea which version of Dermizax I've used (and still use). But I know it does breathe. I'm quite sure I'd never have been comfortable wearing the stuff for well over a year, every day, if it didn't. It definitely does not feel like plastic non-breathable fishing raingear. Of course, it's also much less breathable than not wearing raingear at all. I'm mostly traveling in cold and wet conditions where near-freezing rainy weather could last for many days in a row, and waterproofness is more critical for me than breathability. But I've worn Dermizax top and bottoms every day for a whole year walking between Seattle and the Aleutian Islands (went through 3 sets), and recently for 2 months of fall on a coastal Alaska glacier (that set is still going strong).

The biggest downside I've noticed is that it does hold water. So if the raingear is soaked on the outside, even if it's basically dry on the inside, it's heavy.

The stretchy fabric means that it gets holes far less often than goretex. And when it does get holes, they can be patched, and the whole thing is waterproof again. I haven't tried Paramo (mentioned by others), but Dermizax really does work better than any of the more standard raingear I've tried.

Thank you Erin,

Sounds like Dermizax might be worth a try. It is definitely an interesting fabric.

Unfortunately most garments I can find are not that lightweight and quite pricy.

In regards of holding water, I suppose everything with a worn off DWR will start to hold water. The question is how much more water Dermizax holds and if there is noticable difference compared to any other fabric.

Dermizax is the name for a family of waterproof breathable technologies from Toray. EV and NX are the specific laminates most often seen in apparel. They are monolithic hydrophilic in nature and perform very well, in fact the EV in it's generic form is used as house branded waterproof breathable by more than one big outdoor player. The new NX has 'breathability' numbers off the charts, easily doubling the old EV's performance while being very stretchy and much lighter. Unlike eVent and Neoshell there is 0 CFM through the fabric, which makes it a great cold-windy-cold performer and why the Norwegians like it so much.

To clear up some confusion below. Breathability is really referring to moisture vapor transfer which is measured two different ways, with upright and inverted cup testing. microporous technologies perform better in upright tests,hydophilics test better inverted. No, your jacket will not wick water to the inside without a DWR as long as your big hot body is inside, but you will swear that it is leaking when that thermally conductive cold water gets a millimeter from your skin. DWR is essential for waterproof breathable system to work comfortably and efficiently, but they do work without it. Best,

J1s L1099 A1 breathability ratings

toray Dermizax MP 10,000
Toray Entrant W 10,000

Toray has a number of Dermizax and Entrant variants. The numbvers I have posted are from the Toray web site for the most breathable versions. For comparison Event is about 22,000.

"It seems that it cannot be affected by body oils and salt as much as the more traditional membranes."

The original version of Gortex was just an expanded PTFE membrane. Body oils would get onto the membrane and stick to it. Washing wouldn't remove it. The design of gortex was then modified by adding a very thin layer of polyurethane onto the PTFE membrane to protect it. The protective polyurethane layer also reduced the breathability. Torey just uses a polyurethane membrane without the PTFE layer so body oild will not effect Darmizax, Entrant, or gortex breathability.

Event is very similar to the original gortex. But unlike Gortex the PTFE membrane was modified so that body oils would not stick to it. So if you get enough body oil on a Event jacket to reduce the breath ability, simply washing it will remove the body oil and restore the breathability.

Salt is not much of an issue for any waterproff breathable jacket. Simply soaking the jacket in clean water will desolve and remove the salt.

Note: dirt sticking to body oil and Salt will act as abrasives and evertually damage any waterproof jacket. Cleaning the jacket regularly will prevent damage.

JIS L1099 A1 is an upright cup test, and in such a test methodology one would expect the microporous (eVent) to post bigger numbers than monolithics, (like Dermizax). With the inverted cup test, JIS L1099 B1, Toray shows numbers for Dermizax NX of 50,000+gm/m2/24 (depends on face fabric). This is more than any microporous can move. MVTR numbers change considerably depending on the test method, and there are a handful.

FYI – The 22,000 gm/m2/24 for eVent is a lowest function number, it usually tests a bit higher.

Note eVent's performance advantage is the high MVTR combined with a little surface convection across the face. Dermizax NX's advantage is huge MVTR, light and stretchy and windproof. Each has a slightly different objective.

Summary – There is no single bench test that approximates field use, and no single best fabric. The physiology of the human is the biggest variable, people are dramatically different in their body's response to wearing clothing in rough weather.

(A note about numbers – The industry loves the JIS testing because it produces bigger numbers than the similar ASTM test methods, JIS is run at a higher temperature. Also, look for newer dynamic MVTR and drying rate oriented testing, they are said to have much better field correlation.)

Best,