I hear and read many opinions regarding the import...

I hear and read many opinions regarding the importance of breathability, waterproof ratings and the advantages of each type of membrane/laminate and thought it may be helpful to layout some of the facts and information on waterproof breathable fabrics. 

I put together the following information on waterproof breathable fabrics to help you better understand how they work and in the end hopefully you will understand why we believe so strongly in Toray’s Dermizax technology.

I would love to hear your comments on this information.  

Good luck this season.

Jason

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Overview

Waterproof breathable fabrics work to keep you and your layering system dry while allowing perspiration to exit during exertion. Waterproof breathables typically offered in 2-3 layer fabrics, all of which are all built upon the same principle: the pores of these fabrics are too small for water to get through, but large enough for body vapor to escape. To attain their waterproof breathable properties, fabric makers utilize either laminate technology or coatings.

Laminates are formed when waterproof breathable membranes are bonded directly to the underside garment’s face fabric. An analogy for this process is the idea of wallpaper applied to a wall. Where the membrane (wallpaper) + fabric (wall) = a laminate. Coatings are liquid solutions that provide waterproof breathable characteristics when applied to the face of the garment, similar to paint applied to a wall. All raingear face fabrics are treated with durable water repellent (DWR) finishes to provide extra water protection.


Waterproof breathables commonly consist of an outer layer known as a face fabric (usually made of nylon or polyester) and a laminated membrane or coating made of ePTFE or PU. A third layer consisting of a backer lining is sometimes added to provide abrasion resistance. The purpose of the face fabric is to add color and protection. Although this layer is treated with a durable water repellant (DWR), it is not waterproof. The second layer , the membrane, which has tiny holes too small to let liquid water enter, but large enough to allow water vapor to escape, is the waterproof layer. The last layer in 3 layer fabrics is bonded for comfort. Over the years most waterproof breathable fabrics are all extremely waterproof for any weather activities, but differ in breathability and other dimensions.

Laminates

The core of a laminate is its waterproof membrane. In laminates, the membrane is bonded to the fabric by applying pressure and heat. Membranes are most commonly made from expanded polytetrafluoroethylene or polyurethane films.

Expanded polytetrafluoroethylene (ePTFE)

ePTFE waterproof membranes have microscopic web-like structures that are only about 10 microns thick. Makers of Gore-Tex® have estimated that one square centimeter of ePTFE contains 1.4 billion pores. The pores in ePTFE are about 20,000 times smaller than raindrops making ePTFE hydrophobic (water repellent).

An ePTFE membrane is a low surface energy solid. That means the individual atoms of the membrane are tightly bound to one another. A low surface energy solid will only get wet when it comes into contact by a low surface energy liquid. Water has a high surface energy; atoms in water, while still bound, are not bounded to the same magnitude as low surface energy liquids. When a liquid has high surface energy, molecules tend to pull together in a shape that occupies the least amount of space on other surfaces. So when high surface energy water, makes contact with low surface energy ePTFE, water molecules bond tightly together into round droplets that slide off the surface instead of penetrating through.

There are only two ways that water can penetrate ePTFE- if water is applied with enough force or if the ePTFE membrane is contaminated. Rain during windy seasons exerts a force of about 2 pounds per square inch, which is not strong enough to penetrate ePTFE. Any high surface energy materials can cause contamination: dirt, body oils, sweat, or pesticides. When the membrane is contaminated, the composition of the membrane is altered, causing its surface energy to change. If water molecules come into contact with a high-energy surface, they split open and wet the surface of the material causing leakage. The only way to prevent ePTFE from contamination is to make it oleophobic (resistant to oils).

Gore-Tex®

It is hard to discuss waterproof breathable laminates without mentioning Gore-Tex®. Robert W. Gore discovered that ePTFE could be manipulated into a nearly weightless film, thinner than a trashcan liner. This membrane contained billions of microscopic pores that turned out to be so small, water droplets couldn’t fit through, but water vapor-that is released from the body when you sweat- could. Thus, the creation of waterproof breathables. Today, Gore-Tex® creates its fabrics by laminating their ePTFE membrane directly to a high performance face fabric. While Gore-Tex® was struggling with a membrane design that better allowed moisture to escape, eVent™ was created.

eVent

The eVent™ membrane is formed from ePTFE just like Gore-Tex, but without an added polyurethane film. eVent™ injects the ePTFE membrane with polyacrylate to make it more breathable, but according to fabric experts, less durable. eVent™ fabric maintains your body’s temperature and stays protected from contaminants. Since eVent™ infuses protective ingredients into the membrane, unlike Gore-Tex, that glues a separate layer onto the membrane, eVent™ fabrics have a unique waterproof membrane that allows millions of tiny pores to breathe while being too small for water to soak through. In cold, dry weather, a super breathable shell can actually lead to visible clouds of water vapor exiting the wearer’s body, which leads to heat loss. It is not uncommon for owners of eVent™ jackets, for instance, to need more insulation under their shells to stay warm.

 

In a nutshell here is how Gore-Tex® and eVent™ laminates compare:

Gore-Tex® laminate

eVent™ laminate

  • ePTFE plus anti-contaminant PU layer
  • Excellent waterproof performance
  • Very good breathability
  • Excellent durability
  • Favors higher humidity levels

 

 

  • Coated ePTFE filaments
  • Excellent waterproof performance
  • Excellent breathability
  • Very good durability
  • Tend to be cheaper
  • Performs equally in low and high humidity levels
  • Transfers vapor quicker resulting in heat loss
  • Less likely to collect water on interior of fabric

 

Polyurethane Films (PU)

Polyurethane (PU) laminates are made by laminating a lightweight polyester fabric or 100% woven fabric to a thin film of polyurethane of about one to two millimeters thick. Once weaved together this creates a flexible and breathable water-resistant fabric. Using a thinner laminate helps keep the fabric as stretchy and soft as possible.

PU films allow for good stretch, complete waterproofing, and maximum comfort. As compared to ePTFE, PU films usually result in lighter, smaller-packing garments. PU laminates, unlike ePTFE laminates, can accommodate stretch in a garment’s design and are highly durable. Therefore, these lower cost PU films, may handle hard impacts such as falls better than ePTFE laminates.

PU laminates tend to have many characteristics that set them apart from other waterproof breathable laminates. Some of these general characteristics are long-term durability, flexibility. Additionally, PU laminates are abrasion and oil resistant. Tensile strength measures the stress a material can withhold before breaking while being stretched. The tensile strength of PU laminates can range from 5800 to 9506 psi (pounds per square inch) while the tensile strength of other laminates is around 4000. PU laminates can elongate 800% before breaking compared to the 300% of other laminates. PU laminates possess application flexibility, which means they can be transformed and altered while still retaining flexibility and performance. These laminates remain flexible in temperatures as low as -60°F, which makes them the perfect material for demanding environments.

Coatings

Coatings consist of spreading a layer of polyurethane resin directly onto the fabric. There are two mechanisms to make coated fabrics, microporous or monolithic.

Microporous

Microporous coatings have very small pores that are big enough to allow vapor to pass through, but smaller than a raindrop. This means that perspiration from your skin can easily pass through the fabric, yet raindrops are way too large to soak into the garment. The diameter of microporous coatings range from 0.1 to 1.0 micrometers, a raindrop’s diameter is larger than 3.0 micrometers, but the diameter of vapor is about 0.0004 micrometers.

Monolithic

Monolithic coating is a solid nonporous coating that protects from the wind and will not clog with dirt, detergent, perspiration or dirty water like a microporous coating might. This hydrophyllic coating pulls perspiration off skin, then absorbs the perspiration vapor and disperses it through the fabric, allowing it to be evaporated away from the fabric. 

 Fabrics with coatings and lamination have about the same level of durability, but coatings come off gradually while delamination (the separation of laminated layers of fabric), once begun, happens more rapidly.

Measurements

The terms waterproof, water resistance, wind resistance, and breathability refer to specific conditions that have been tested for in a laboratory. Products are usually given two ratings, the first is a measure of how waterproof a fabric is and the second of how breathable the fabric is. When comparing measurements it is important to make sure you are comparing measurements with the same scale. In order to be waterproof by definition, a fabric is only required to withstand over 1,000 mm of water pressure without leaking; therefore, it is important to learn the ratings.

Waterproof rating

Water resistance is measured by the pressure of water, in millimeters (mm), that can be kept out of the fabric for a 24-hour period of time. Once a fabric is rated at least 20,000 mm/24hr it is completely waterproof.

Waterproof Rating (mm) Resistance provided What it can withstand
0-5,000 mm No resistance to some resistance to moisture Light rain, dry snow, no pressure
6,000-10,000 mm Rainproof and waterproof under light pressure Light rain, average snow, light pressure
11,000-15,000 mm Rainproof and waterproof except under high pressure Moderate rain, average snow, light pressure
16,000-20,000 mm Rainproof and waterproof under high pressure Heavy rain, wet snow, some pressure
20,000 mm+ Rainproof and waterproof under very high pressure Heavy rain, wet snow, high pressure

Breathability

One of the problems with breathability measurements is that there is no universally accepted standard. Therefore, when comparing breathability measurements consumers may not be aware that they are not comparing equal measurements. One frequent measurement for breathability, however, is the grams of water that can move through a square meter of fabric over a 24 hr period (g/m²/24hr). Below are the ratings of Toray’s® waterproof products compared to others on the market.

Brand

Product

Waterproof Rating

(mm/24hr)

Breathability Rating

(g/m2/24hr)

Toray®

Dermizax®NX

20,000+

50,000+

Toray®

Dermizax®EV

20,000+

20,000

eVent

eVent

30,000

22,000

Gore-Tex®

PacLite®

28,000

15,000

Gore-Tex®

Performance Shell

28,000

17,000

Gore-Tex®

Pro-Shell 3-Layer

28,000

25,000

Marmot

MemBrain®

20,000

25,000

Marmot

PreCip®

15,000

12,000

Marmot

PreCip Plus®

25,000

15,000

Mountain Hardwear

Conduit

20,000

20,000


Toray’s ENTRANT Dermizax
® EV

Toray’s ENTRANT Dermizax ® is a polyurethane non-porous lamination with over a 200% stretchable membrane and a soft hand that offers excellent flexibility. This “soft hand” is one of the most important advantages of microfibers because they provide extreme comfort to the consumer. Toray’s 3-layer breathable waterproof membrane is quieter and more durable than anything else on the market. Toray’s Dermizax® EV has 20,000mm/20,000 g/m2/24hr waterproof and breathability ratings. This is what we have previously used in our Chugach Rain Gear with fantastic results.

Toray’s ENTRANT Dermizax® NX

Toray’s latest technology, Dermizax® NX, sets a new standard for waterproof breathable membranes. The membrane is completely wind and waterproof, up to 200% stretchable and more breathable than any comparable fabric. Compared to Toray’s previous leading waterproof breathable membrane, Dermizax® EV, the breathability ratings have more than doubled from 20,000 g/m2/24hr to 50,000+ g/m2/24hr, which is clearly higher than any other known rating.

One unique aspect about Dermizax® is that all of the other product characteristics remain unaltered. That means the new Dermizax® NX has not lost any waterproof or windproof abilities with the added breathability. The Dermizax® NX membrane is manufactured completely in Japan and undergoes strict production and quality controls. Dermizax® membranes are non-porous PU membranes, which are developed so they can be controlled exactly and arranged in structures that strengthens the diffusion of water vapor molecules, increases that transmission rate, and leads to higher respiratory activity. This makes the Dermizax®  NX membrane the perfect membrane for waterproof breathable gear.

 

This article has 43 comment(s)

  1. Matt

    Good info Jason. Would like to see some information on your expectations for both the Chugach and the Yukon line of rain gear in terms or durability and long term performance. I guess my real question is a bit more specific. I have a 3 year old Chugach jacket; when should I expect performance to start to deteriorate? Assuming most, if not all, of these fabrics can only last so long. ??

    Also, what is KUIU’s recommended approach for cleaning your rain gear? Do you add suggest adding something like the Gear Aid ReviveX Waterproofing Soak at some point, or does that cause more damage than help to your products? I don’t want to cause any damage to the gear, but also want to maximize its use.

    Appreciate the info. Good luck on your trip North. 😉

    • Jason Hairston

      Hi Matt,

      Great question. Your Chugach Gear is expected to last a very long time depending on how hard you use it. I recommend washing your rain gear on a regular basis as it keep the membrane clean and a warm (not too hot) tumble dry will recharge your DWR. All of the ReviveX products are great, but not required.

      Jason

      • Matt

        Thanks Jason. Any particular soap that we should use on the rain gear? I wash my gear after each trip and have been using various “sport” detergents, but was curious as to what KUIU recommends.

        Or, does any old free and clear laundry detergent work just fine?

        Thanks,
        Matt

    • Jason Hairston

      Just a regular laundry detergent will work just fine.

      J

  2. Matt Clark

    Hi Jason and company, I was wondering if you could post a more subjective comment on the breathability. For instance, if you are climbing steep slopes in 50 degree F temps, and sweating a lot if you are me anyhow, how much of that perspiration is going to make it out of the jacket. I’m not imagining it will work miracles but my experience with older gore-tex shells is that it really doesn’t work for me while hiking unless it’s really cold out.

    I just received my Guide DCS Jacket in Verde, my first piece of Kuiu gear, in the mail. I took it on an elk scouting trip for two days, It is awesome, absolutely the best jacket I’ve worn in the field!

    Thanks,

    Matt

    • Jason Hairston

      Hi Matt,

      It is hard to be subjective without it just being an opinion. I can tell you the new NX we have in the Yukon is absolutely amazing. It breathes like nothing else I have worn before and everyone who has worn it has the same opinion. It is light years a head of what you experienced in your old Gore-tex shells. Glad to hear you like the Guide Jacket.

      Jason

  3. Les Butters

    Jason,
    Great and informative article…
    When speaking about breathability; is there a temperature delta created by body temperature (vapor) to the outside temperature that relates to the transmission rate of the water vapor? Is breathability between the product you mentioned a concern when the outside temperature is similar to the (interior) body temperature. (Warm summer rains…).
    Best Regards,
    Les Butters

    • Jason Hairston

      Hi Les,

      Great question. Yes, for micro-porus membranes like Gore-tex or eVent this can certainly cause a problem because the membrane requires this delta to function. The Dermizax technology actively moves moisture from the inside of the membrane to the outside of the membrane.Another advantage is Dermizax does not require the moisture to in in Vapor form to move through or across the membrane.

      Jason

  4. Joe

    Jason,
    Great write up. Now when will the yukon gear be back in stock. Headed on an elk hunt in September and would really like to get it before then.
    Thanks, Joe

    • Jason Hairston

      Hi Joe,

      You must be waiting on the Mediums. I do not have a date for restock yet.

      J

  5. Darryn

    Thanks for the technical information. I bought the Yukon set and will be putting it to the test on a return trip to Northwestern BC for grizzly bear. It will be replacing an eVent set so I will be able to compare its performance. I will also be able to reduce my overall outer wear requirement because of it’s wider spectrum of usage, thus reducing the overall bulk. Perfect for extended backpack hunts with limited space. Thanks for your passion to embrace these types of technologies and bringing them to those that can benefit from them greatly at a reasonable cost.

    • Jason Hairston

      Thanks Darryn! The Yukon allows me to eliminate my Attack Pants and Guide Jacket from my gear list as well. I look forward to hearing your opinions after your hunt. Good luck and be safe.

      Jason

      • Matt

        Jason,

        Look forward to seeing your gear list for upcoming hunt. Specifically interested in how the new lines have changed things up for your chosen line up of gear.

        Matt

  6. Roccabilly

    Great info! Does the Yukon gear have a soft outer layer? I have a Sitka Stormfront lite jacket and it is loud! it nearly cost us a bull elk in the rain 2 years ago. I am going to get a Yukon outfit soon, I need size large for both. Any ideas when you will get more vias camo Yukon jackets in?

    • Jason Hairston

      It is quiet, especially compared to the Storm Front Lite.

  7. Mark

    Jason,

    What are the breathability ratings of the KUIU garments AFTER Vias/Verde printing? Has this been tested?

    Thanks,
    Mark

    • Jason Hairston

      It is the same. The printing and finishing on the face fabric is done before bonding and does not change the CFM characteristics of the fabric. Yes it has been tested.

  8. todd

    Jason,

    How does cocona stack (first lite’s new stuff) stack up with this membrane?

    Thanks,

    Todd

    • Jason Hairston

      There no data on the membrane First Lite uses. I am not sure if it is a ePTFE or a PU membrane? First Lite calls it a Cocona membrane. Cocona is an additive to fabric that is made from burned coconut shells that claims to help evaporate moisture faster. Cocona is not a membrane manufacture like Gore-tex or Toray Dermizax, so I am confused by First Lite’s information. First Lite states a 30,000MVTR rating on their website.

      Dermizax NX is the most advanced membrane ever made and Toray supplies the data to back up their claim which is why we use this membrane.

  9. Oliver

    How does the Yukon Series compare to Polartec Neoshell

    Thanks, Oliver

    • Jason Hairston

      Neoshell sacrifices waterproofness for breathability. A 10,000mm Hydrostatic Head test is the minimum requirement to claim a product is waterproof, which is Neo-Shell’s rating. I have tested membranes with a 10,000mm rating that I have been able to “push” water through over time. I think Neo-shell is a great choice for snow sports or other light recreational sports.

  10. Roccabilly

    Great thanks Jason! Now i just have to wait patiently for more yukon jackets to be built 🙂 Our BC bighorns are in trouble next month. Happy and safe hunting to ya!

    • Jason Hairston

      Your welcome! Good luck on your hunt. I am heading to the NWT on Sunday. Kind of hard to get work done around here!

      J

  11. Kevin Dill

    I’m thinking that I read where ‘typical’ laundry detergents must be used with care when washing DWR treated fabrics. I believe this is because of the possible exposure to surfactants which will lower the surface tension of water and result in it spreading out across the fabric, as opposed to beading and running off. Trace amounts of surfactants left on fabrics can perpetuate the ‘wetting out’ of a fabric’s surface…thereby lowering it’s breathability. The tech-wash products I’ve used typically tout their lack of surfactants as being important to the garment’s subsequent performance after washing.

  12. Adam

    Nice write up. So, why not use the new Dermazax NX with the Chugach line as well as the Yukon line? The Yukon stuff looks awesome, but I personally like the weight of the Chugach line for my needs…but the NX is clearly superior to the EV.

    • Jason Hairston

      Thanks Adam. We will be making an announcement and release of Chugach NX next week.

      Jason

  13. Ron P

    Jason, Is the Chugach line being discontinued? If so, what is replacing it?

    • Jason Hairston

      It is being up-dated. There will be an announcement next week.

      Jason

  14. Bryan

    I called in and was told no plans for solids in the chugach. I have vias in everything but want solids for my rain gear. I really would like a 3 layer hard shell that is pack able but able to use as a primary layer if I want. If this cant happen buy late winter to spring I will have to go elsewhere. Please bring back solids!!!!!!

    • Jason Hairston

      Customer Service does not have all the information. We will bring back solids in Chugach. Hang tight.

      Jason

  15. Shane Close

    This is a great write up. Part of me is sad because now my Chugach set will be outdated, but the flip side is that it’s still better than 99% of stuff out there. And I’m sure that once my Chugach set does kick the bucket there will be something even better out. I’m excited to see the continual innovation coming from kuiu. Keep up the great work!

    • Jason Hairston

      Thanks Shane. Actually your current Chugach 100% better than stuff out there:) Except the new Chugach NX that comes out this week.

      J

  16. James

    Very happy to hear that KUIU is constantly updating their lineup to give customers the best gear available.

    Jason, will the new Chugach gear be priced around the same as the old stuff?

  17. Jason Hairston

    Yes, exactly the same. It is more expensive to KUIU but I did not want to increase the price for our customers.

  18. Dennis Donati

    That was an awesome article and break down of the different materials and their limitations and uses. I am excited to try the new Chugach or Yukon line, I just have to decide which one to go with for western WA and our wet winters. I like the fact that these items can reduce the layers needed to make a complete system, which frees up valuable space and weight for pack trips. I have been thoroughly impressed with every piece of gear I’ve tried that has the Kuiu name on it. Looking forward to trying more items out. Will these new fabrics be used for the next round of gators, and when might those be back in stock?

  19. Bryan

    Hanging tight, looks like Iam having hip surgery and will be off work for 6 months. Guess I don’t have a choice 🙂

  20. Billy W

    Great article on waterproof and breath ability of fabrics, thanks for taking the time to explain it.

  21. Toby

    Hi Jason

    I have a DCS Guide jacket which I think is awesome, my only issue with it is it holds odour. I layer with your merino base layers, they dont smell but the jacket does….even after one day. My question is will the inside of the Yukon jacket be similar to the guide jacket?
    Thanks

    • Jason Hairston

      No the Yukon Jacket is a 3 layer hardshell. The Guide Jacket is a soft shell which is micro-fleece on the inside.

      J

  22. Pingback: Comprehensive Rain Gear Reviews | Remote Pursuits

  23. ZAK

    Hi,
    I am a skier, I got here when I was searching for Demizax NX which I found in some high-end jackets (like Kjus).
    I needed 2 jackets. A shell jacket which I ended up buying from Arctryx, and another one for an active life style. I walk to work, 35-40 min each way, and I need a breathable jacket for winter.
    I know you make these for hunting. But skiing is a mountain activity and skier have almost the same need as a hunter (maybe we need a different mid layer but the rest should be the same).
    Almost the same for my need for an active life style

    Lot of people like me will appreciate some good quality clothing which is priced reasonably. you already have experienced, did the research and use the best membrane and best insulations, maybe you just need new colors and a little change in design for a new series. The rest is marking. just look at some ski, and climbing brand Arctryx, Black diamond, Patagonia, and Kjus.
    I should pay almost double for the same quality in the ski market if not more!!
    I may not buy another ski jacket for the next 5 years 🙂 but maybe the next person does!

  24. Jason

    I’m looking at the Chugach NX raingear for an upcoming hunt and was wondering if you considered reinforcing the knee and seat portions of the rain pant? Any feedback and comments on durability of knees and seat areas which can wear out more quickly? Thank You

    • KUIU Ultralight Hunting

      Hi Jason,
      It sounds like you might be better suited for the Yukon NX which has both reinforced knees and seat for more durability. If you have questions about the differences between the Chugach NX and the Yukon NX, please give our customer service a call at 855.367.5848 and they will be able to help you choose which system will best suit your needs. Thank you for supporting KUIU!
      Jason