Outerwear 101

Performance Ratings Debunked

So now you’re thinking, “If the DWR determines the waterproofness of my outerwear, then what is up with this 20K number for waterproofness?” The answer is that any laminate with a waterproof rating of about 10,000mm will keep you very dry in all but the hardest downpours and gale force winds. However, you will only experience the actual waterproofness of the laminate if your DWR fails. This makes qualifying the importance of the actual performance number very difficult. We will look at how these ratings are actually calculated, then deconstruct their usefulness to the average consumer.

Waterproof ratings, what do they mean?

20,000mm: what the hell does that even mean? This one is deceptively simple. It means that this membrane will not leak when exposed to the pressure generated by a 20,000mm-tall column of water. Simply, all that the waterproof rating means is the membrane can withstand a certain amount of pressure from water before it leaks. (And FYI, 704mm of water = 1 psi.)

Breathability ratings, do they really matter?

15,000g/m²/24 hours.

Ummmm, what?

This number specifies that over the course of 24 hours, 15,000 grams of water vapor can pass through a one-square-meter section of the laminate. Seems pretty simple, but it is not at all a simple number to measure. There is no standardized technique for measuring breathability. Therefore, companies will often use a test that provides favorable results for their particular product. This makes a comparison of breathability values from different companies completely useless, since various testing procedures can produce huge performance discrepancies.

A membrane that tests to 8,000 g/m²/24 hours on one test could produce 28,000 g/m²/24 hours using a different test method. For this reason, many companies do not release these test results. In reality, breathability ratings mean pretty much nothing. Isn’t that comforting?

So now the extremely confused consumer asks, “If neither the waterproof rating nor the breathability rating are all that useful, then how in the world am I supposed to find a good jacket?”

Basically, you’re going to have to place your trust in a product at some point; test numbers and marketing may only mislead you in the end. There are two choices you have to make: which manufacturer, and which fabric?

Manufacturers fall outside the scope of this article, but whether it is Burton or Arc’teryx you’re considering, my best advice is to remember you get what you pay for.

Fabric, on the other hand, is something we’ll discuss:


The good: GORE-TEX spends millions of dollars in R&D every year. They make absolutely bomber products and don’t skimp on the technology. GORE-TEX guarantees every product made with their fabrics to be 100% waterproof for the life of the garment, and chances are good that you will never have to cash in on that guarantee because their products work really, really well. Gore works with some of the best manufacturers in the game, and currently has what many would consider a monopoly on the high-end, waterproof/breathable garment market. Their products work, simple as that.

The bad: GORE-TEX is really expensive. Because of their huge influence and their general lack of competition, they can charge extremely high prices for their fabrics. Also, because of the PU layer in their technologies, they do not breathe as well as their main competitor, eVent. GORE-TEX claims, however, that this difference in breathability is not noticeable to the consumer, and to corroborate that claim, GORE-TEX products often receive rave reviews for their breathability.


The good: The eVent membrane performs extremely well. It has the best breathability of any technology currently available (even if just barely) and has great waterproofing to match.

The bad: You’d think that, with a better technology than Gore, eVent would be a huge contender in the waterproof / breathable game. Unfortunately, there are many issues that keep eVent from posing a true threat to GORE-TEX fabrics, and the first is the cost: eVent is still extremely expensive.

But an even bigger issue lies in their production: historically, eVent has had trouble meeting production schedules from manufacturers, which is a large deterrent for business.

The third issue is a manufacturing one: GORE-TEX licenses companies to use their product, and it isn’t easy to get a license. If a licensed Gore manufacturer produces a piece using eVent, they can say goodbye to their Gore license, and companies can’t afford to lose their Gore licenses for a fabric with only a slight edge in breathability. Finally, eVent’s oleophobic coating can be fouled over time, causing leakage through the membrane. eVent garments have to be carefully and frequently washed to maintain their performance, unlike GORE-TEX products that are truly waterproof for the life of the garment.

PU, the Workhorse

The good: PU laminates are cheap to produce, are extremely durable, cannot be fouled, and are very common (i.e., there are a lot of styles to choose from). They can be manufactured to many different specifications, so they are found on all sorts of products ranging from price-point Walmart specials to the highest-end Patagonia pieces.

The bad: The performance just isn’t as good as the name brand membrane. Because you can only make a standalone, PU laminate so thin, it is the least breathable membrane of the bunch.

36 comments on “Outerwear 101”

  1. Freaking killer articles. All of them. Even as a seasoned gear shop employee and tech junkie, can always count on Blister to deliver the goods on beta, science, and the layman’s terms to tell the whole story.

    Keep up the really really ridiculously awesome work.


  2. Wow. Technical yet totally accessible article. Great, great read for anyone looking to buy waterproof, breathable gear. I learned a lot & will try to spread the word about this article. Thanks!

  3. Really in depth article, but really useful even for the non technical out there. You covered some great points. Time to go shopping for the right balance of tech in my new jacket! I’ve shared this on our Facebook, will be really useful to our followers.

  4. Terrific article! Might I suggest for Outerwear 102 and article about actually dressing for skiing/boarding? How are the various layers supposed to be used? What do you guys wear for different conditions? Two layers? Three layers? How should you layer under a shell? Think would be a useful companion. Keep up the great work!

  5. Great Article!
    Was just about to buy 3L Gore pants… Questioned my choice (and the price)… Found your article… Read the whole thing… And just ordered the pants!
    It confirmed my decision — also answered my long wonder about how the 20k/20g (etc) ratings compared to others and if they really could be trusted. Answer = no more board shop employees trying to sell me over priced claimed “technical” wear.

  6. This is a fantastic article. Where does Dermizax fall? I keep seeing the material in very high end Kjus ski jackets; is it simply a PU laminate? If so, I can’t imagine the performance would warrant the $1500 price. They claim incredibly high breath ability scores, but thanks to your article I now know to ignore them :) There also appears to be several versions of Dermizax. Is this material any good?

  7. Great article, nice to see one of these that doesn’t spew the misinformation of water drop vs vapor molecules through holes stuff.
    The one thing you didn’t stress was the effect of shell and liner fabrics on breathability of the total laminate.

    • Hey Slim,

      That is definitely a huge part in the total breathability of any garment. A bit difficult to baseline, but certainly a huge factor. Thanks for your comment!


  8. stupendous and layman friendly article! it took me a few minutes to fully absorb (he he) all this ‘dry as a bone’ information to great effect. no ‘watered down’ or fishy patent references to get wallowed down in either! wish there were more ‘commercial’ PR folks who had the smarts to actually divulge facts, rather than foist their marketing jargon upon so many naive buyers!

  9. So far what I’ve read on this site has been very useful, and I like the writing style. I don’t think I’m the only one around that is sick and tired of being treated as an imbicile, or worse, just a source of income by sometimes dishonest outdoor companies that are run by the marketing departments. Even companies like Patagonia, TNF, and others that started off right, by climbers and such, have gone far astray, letting the marketing departments and “the bottom line” affect their decisions.

    Hell, Gore’s lies have killed people, hypothermic in their own sweat. How the f__k is that “keeping you dry”? Meanwhile they have made billions.

    Good to see a honest, independent source of information. I hope you continue.

    Got anything on Pertex Equilibrium, by chance?

    • Hey Alvin,

      Pertex Equilibirum is a non-laminated (no membrane) fabric that acts like a very thin softshell. It is typically used in very lightweight garments and is not waterproof.

      Like most non-laminate softshells, Equilibrium claims “weatherproof”-ness by using a high density weave on fabric exposed to the elements.

      What makes Equilibrium a higher performance fabric than some others in this category, is the use of a denier gradient to facilitate breathability by capillary action throughout the fabric.

      Basically, the inner layer of the fabric (against skin) is woven with a larger diameter fiber than the outside layer. This creates a driving force for capillary action out of the garment for breathability.

      I hope that answers your question,

  10. Is it just me, or is DWR way, vastly, overrated? I’ve had any number of pieces with DWR. Typically they stop working within minutes of a light rain, even when new. Of course it gets worse after even just a couple washings. And I buy good quality (in every other way) expensive stuff (Patagonia usually, also Arcteryx, Lowe Alpine, others)…I’ve yet to see DWR work properly. Ever.

    • DWR is a tricky thing to nail down. The performance depends on many things. When you have Patagonia claiming to put the same DWR on their M10 3L hardshell as a pair of casual pants, there is obviously going to be some performance differences.

      In many ways, the fabric that the DWR is on is just as important as the DWR itself. Low density weaves, stretchy and high denier fabrics (like a lot of casual clothing) typically don’t have the same DWR performance as high density weaves on laminated fabrics.

      Bottom line: DWR is essential to your hardshell, not so much to your “softshell” crag pants – and even then, performance varies wildly.

      • thanks, that makes a lot of sense. Even still, I haven’t had much luck with DWR on anything at all, honestly. My hardshell always wets out on the surface, and then doesn’t breathe, or even in cold weather sometimes becomes a sheet of ice-fabric.

        It’s funny but just today I recieved email from a well-known, highly experienced outdoorsman who I happened to ask some of these questions to, and he told me he often uses an umbrella!

        Others suggest those cheap plastic ponchos. That says a lot about the state of these “high tech” (and ridiculously over-priced) garments, I think. You can buy a lot of umbrellas and ponchos (or Hefty Bags!) for 600 bucks, eh?

        • You know, that is a great point to bring up. Depending on what you’re doing outside, often an umbrella or poncho is all you really need. Hardshells do NOT excel in rain, they just don’t work well for many reasons. If you’re in the rain and don’t need both hands, or aren’t sweating extensively, there are other options.

          The reality of the situation is that 90% of the time you’re outside, you don’t need anything more than wind protection. In heavy, wet snows and rain — the other 10% — you need the protection of a hardshell. But most people (including me) go out in a hardshell almost everyday… Something I’ve been pondering a lot lately. Can a non-hardshell based layering system catch on in mainstream snow sports?

          • I had heard they already are popular in skiing and snowboarding, when the lodge is right there. I don’t believe a hard shell is all that necessary in snow for a few reasons: 1. snow takes time to melt, and brushes off easily, 2. snow is 90% air anyways, 3. in the cold, humidity is lower (i find things dry quite fast in the winter, IF they ever get wet in the first place, that is) 4. you don’t sweat as much in the cold, leaving the insulating and wicking layers with only external moisture to deal with 5. i had another one but forgot it right now kk

            It seems to me, from experience of myself and others, and just logic, that the only truly difficult conditions to deal with (from a clothing perspective anyways) are sustained, cold rainy conditions, with temps above freezing up to the low 50s or so. And only then, really, when you stop hiking. As long as you are moving, you are generating plenty of warmth, and continuing the evaporative process. As soon as you stop either the rain that soaked in, or the sweat under a hard shell immediately makes you start chilling, and fast.

            That’s my opinion, and I am going to start testing some soft shell combos when i get the chance in those kind of conditions. Honestly, how often do you get those kind of conditions? Not much, thankfully. But I plan to seek them out as soon as my new Equilibrium shell gets here! ;)

          • There is one garment that works well in chilly, wet conditions…the old school wool sweater, the think, airy kind (knitted i guess)…those things keep you comfortable in all kinds of conditions, and don’t over-heat readily. I’m sure the Llama ones in the Andes and the Yak ones in the Himilaya must just be superb, since those places are cold and people live up to 6000m above sea level.

            Someone should really start researching this more and try to produce things of this nature commercially. I’m not sure what Sir Edmond wore, but I bet there was wool, maybe even Yak wool, involved…and clearly his porters were using that. Heck, they didn’t even have polyester in those days, I don’t think! :-D

            • Yes, if anyone knows of someone making Yak-wool sweaters, let me know. Maybe it could then be lined with micro-fiber and shelled with Pertex too…oh that would be great….heavy as hell, but great.

  11. Brilliant article. It means even for an accomplished tailor/seamstress diy’ing a good shell that functions properly will take some thought and care. Tips on what to look for in terms of construction of a commercial garment would be great.
    Many thanks!

    • Hey Rosanna,

      I assume you’re looking for a commercial garment for inspiration in making your own? My advice would be that quality is less of an issue than simplicity.

      If you’re making a 3L shell, precise patterning is essential, so much so that most major companies laser cut their fabric. The margin for error is tiny.

      If you’re making a 2L shell, again, keep it simple! These garments can get extremely complicated!

      Let me know if you have any other questions! I have commercially produced both 2 and 3L shells and may be able to answer your questions.


  12. Great article, one of the best i have ever come across. i just wanted to add a nit-sized comment – i have a Patagonia 2.5 layer ski jacket with the “H2No” membrane, and just a mesh liner that is not laminated to the membrane, but just hangs loose in the garment – I thought that was what was meant by the half-layer, but i see it’s used to describe a variety of materials and construction that is more than 2L but not quite a 3 layer build, either. so… Veritatem dies aperit… thanks again for the very informative article!

  13. Fascinating! Thanks for the article. It’s so refreshing to have someone putting solid content out there. Most big publications could learn a lot from what you do. I’ve come to realize that soft shell jackets and pants with the right layer(s) underneath and a good or refreshed DWR finish are the most comfortable in all but the worst weather. Some trips are too remote or long to rely on soft shells but most are not.

    • Hey Greg, thanks for the kind words!

      I definitely agree with your take on softshells. My go-to kit is all softshell. In 90% of the conditions I face, hardshells are overkill. We are keeping our eye on some companies making super light emergency hardshells (some that are under 5oz) that look interesting — throw them in your pack as a precaution and wear your softshell. Kind of a cool concept!

      • Can you elaborate on your standard kit a bit? I’m sure I’ve seen you write about / heard it on the podcast before but I can’t recall the details. Currently I’m skiing about 75/25 resort/touring and starting to figure out that the gear I need to be comfortable on the ascent needs to be lighter and more breathable that what I’ve been rocking. I’m wondering what direction to go for a complementary outer layer since I’ve already got a patagonia snowshot, which does seem fine for the down but is pretty bulky. I’ve got a handful of midlayers so I feel OK there. Would you go for a softshell here or look to upgrade the hardshell?

        • Hey Ari,

          Unfortunately, I test so much gear that I never get to settle into a “standard kit” these days. That said, for 50/50 (or 75/25) kit, I would generally think like this:

          Jacket(s): I think a midweight 3L hardshell with a roomier cut is generally a good, versatile option. When I say midweight, think 500-700 grams (size Medium). If you live in a drier area (like Colorado), then I would go with something air-permeable. On the coasts, I’d stick to a more protective shell. For mid-layers, I’m a huge fan of active insulation. The Patagonia Nano Air line has lots of options but it is far from the only active insulation on the market anymore — shop around and find something that fits well and is the right warmth for where you ski. For ski touring, I like to add a softshell to this kit. My current favorite is the Patagonia R1 TechFace, but that piece works best for very high output days. Something with a bit more weather protection is generally best for the average person.

          Pants: I like to have a pant that is a bit more protective than my shell. I’m often kneeling/sitting/falling in the snow so the pant tends to get a bit more abuse. Again, I would go with a midweight 3L pant but I would prioritize large vents and fit/comfort over the “highest” tech fabrics.

          Hope that helps!

          • Awesome, this is super helpful. I’m on the east coast and ski Colorado or Utah a couple times a year. I do think 3L shell is the right way to go but was maybe thinking of trying eVent. Might not be enough for an all around shell on those brutal VT days though.

            Thanks for the comment.

  14. Great article. I have been wearing an Arcteryx hard shell with a base layer and an atom jacket for skiing. Comfort wise, I’m plenty warm and never feel sweaty. The problem I’ve noticed, however, is that the hard shell is trapping moisture inside. I had been keeping my phone in the breast shell pocket and after a few runs, I noticed my phone was wet. Considering it was about 25 degrees at Deer Valley, I knew the moisture was coming from me. The base and middle layer were functioning as designed but the Gore Tex shell was trapping the moisture in. I guess I could have opened the pit vents but I never felt warm enough to want to open the vents.

    I think switching to a soft shell product is going to make more sense.

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