Introduction
My backcountry layering system has evolved through the years. I’ve replaced wicking garments with hydrophobic garments, I place a high value on air-permeable fabrics, and I prefer to spend a little extra weight on ventilation. My goal with these choices is to assemble layering systems for inclement conditions that allow me to stay comfortable. For me, comfort is most challenging in the blustery conditions I experience where I hike the most – the Rocky Mountains of Colorado and Wyoming.
In this article, I discuss some of the challenges that an effective layering system needs to address. I also highlight a handful of the layers that I use the most and how I combine them into various ensembles for different use cases.
The Issues
Thermal comfort
During physical activity, your body generates heat. In addition, heat is absorbed by your clothing when you are exposed to warm temperatures and direct sunlight. That heat must leave your clothing system in order for you to remain comfortable.
Likewise, during periods of inactivity in cold temperatures, heat loss can make you uncomfortable. Heat loss to the environment is exacerbated in wet conditions (evaporative heat loss), windy conditions (convective heat loss), and when exposed to a clear night sky (radiative heat loss).
The movement of heat from inside your clothing system to the outside environment is critical for maintaining thermal comfort. Heat moves through a clothing system in response to convection (air movement in the system), conduction (the transfer of heat along fabric surfaces from warmer to cooler temperatures), and radiation (e.g., heat loss to an open night sky or heat absorbed from an open sunny sky).
Moisture accumulation
During activity, your body generates moisture in both vapor and liquid (sweat) phases. The movement of sweat from your skin surface to the environment occurs in response to complex processes that involve evaporation, condensation, and capillary movement along fiber surfaces (wicking). Likewise, the movement of moisture vapor through your clothing occurs in response to convection, diffusion, and vapor pressure differentials.
The extent to which moisture accumulates in your clothing will depend on the hydrophobicity (or hydrophilicity) of fiber surfaces, capillary forces within the fabric structure, fabric porosity, air permeability, diffusion (breathability) resistance, and mechanical ventilation features.
Storm protection
Protection from wind and precipitation requires tightly-woven fabrics (for wind resistance) and waterproof coatings, membranes, or laminates (for waterproofing). The fabric physical characteristics that are required for keeping Mother Nature’s elements out also keep your elements (the heat and moisture generated during activity) in.
Sun exposure
In Managing Sun Exposure in the Backcountry, we study how fabric materials and engineering influence clothing’s resistance to the penetration of ultraviolet radiation from the sun. Because I live at and spend most of my trail time at altitudes in excess of 8,000 feet (2,440 m), I’m attentive to the amount of cumulative sun exposure I get. My normal summer hiking uniform includes a long-sleeved shirt, brimmed hat, neck gaiter, sun gloves, and long pants.
There’s an inverse relationship between sun protection and thermal comfort. The tightly woven fabrics that prevent the penetration of ultraviolet rays also inhibit the movement of heat and moisture.
Biting insects
High-thread-count (tight weave) woven fabrics are more resistant to puncture from a mosquito’s proboscis than knitted fabrics. However, knitted fabrics are generally more air-permeable and more comfortable to wear in warm conditions.
As with sun protection, there’s an inverse relationship between biting insect protection and thermal comfort.
Scrambling & Bushwhacking
Most thru-hikers and other trail followers don’t often have to consider the impacts of traipsing through brush or scrambling on rocks. Both of these activities can abrade, puncture, and tear clothing. Clothing that is most resistant to damage (more durable) will be made with higher-denier fibers and tightly woven. Of course, those factors interfere with the clothing’s ability to facilitate the exchange of heat and moisture and your ability to remain comfortable during activity and warmer temperatures.
My Strategy
I tend to gravitate towards layers that are more hydrophobic, dry faster, are more air permeable, better ventilated, and have high insulation-to-weight ratios.
Hydrophobicity
In Do Moisture-Wicking Fabrics Work? and Why is My Base Layer Soaked? Stephen Seeber explored the relationship between fabric hydrophobicity, wicking, and moisture movement in base layer apparel. One of the conclusions from his testing:
“The most critical element of a wicking fabric is how well it allows sweat to be drawn away from the skin, converted to moisture vapor, and then transferred out of any clothing layers. This element is different from how well the fabric itself wicks. How well the fabric wicks does not determine whether you will be comfortable. The disposition of sweat to the environment depends on much more than whether a wicking fabric can absorb lots of moisture in a laboratory test.” – Stephen Seeber [source]
The data from these studies suggest that wicking per se (the capillary movement of liquid moisture along a fabric surface) may actually increase moisture accumulation and hinder moisture transfer out of your apparel system. Of course, it will depend on the breathability, air permeability, and ventilation features of other garments in your clothing system as well.
However, this work suggests that more hydrophobic base layer fabrics may not only absorb less moisture and dry faster, but their notable lack of wicking may also contribute to more comfort and more rapid expulsion of moisture from your clothing system.
My preferred base layers are made with polypropylene, a hydrophobic fiber, rather than polyester, which is more hydrophilic. Because most insulating mid-layers are made with polyester, I look for open-weave fleeces (e.g., Polartec Alpha), which don’t promote wicking to the extent that more tightly woven or knitted fabrics do.
Rapid dry time
Garments that are thin, light, and made with hydrophobic fibers will absorb less moisture and dry faster than garments made with fabrics that are thicker, heavier, and made with hydrophilic fibers. Rapid dry time is an attribute that can be correlated to moisture transfer out of a clothing system. In addition, rapid dry time may be valuable for users who risk water immersion (e.g., packrafting, river crossing).
My fastest-drying garments are fishnet, open-weave fleece, and shell fabrics made with 7 to 15 denier fibers.
Air permeability
Air permeability contributes to the evacuation of moisture vapor from a clothing system by allowing the vapor pressure gradient on either side of the fabric to create convective (moisture-laden) air movement across the fabric surface. I prefer wind shirts and rain jackets that are at the higher end of the air permeability spectrum in those product categories.
Likewise, the three base and insulating layers I own and use regularly (Brynje fishnet, Finetrack polyester mesh, and Polartec Alpha) are highly air-permeable and facilitate convective moisture vapor movement through clothing without having to rely on wicking.
Ventilation
Mechanical ventilation has been discussed in depth previously and is a critical feature of outer shell layers. Ventilation promotes the exchange of large volumes of warm, moist air inside a clothing system with the cooler, drier air of the outside environment. Ventilation, air permeability, and breathability (the diffusion of moisture vapor through a fabric) are all important processes involved in evacuating heat and moisture from a clothing system. However, ventilation has the ability to move the most amounts of warm, moist air in the least amount of time. I’m a big fan of mechanical ventilation features – pit zips, full-length zippers, and adjustable cuffs/hem/hoods – on shell layers.
Insulation
When it comes to insulation for active use (while I’m hiking), I want insulation that has a high warmth-to-weight ratio but is highly air permeable so it’s capable of allowing heat and moisture to escape rapidly when I open vents on an outer shell layer. For insulation while inactive (at rest or in camp), I look for insulations and garments that maximize loft-to-weight ratio and that use shell and lining fabrics that are as light as possible.
My Layers
Trekking Shirts
- Patagonia Long Sleeve Sun Stretch Shirt – polyester, tight weave, resistant to biting insects, not very air permeable.
- Jolly Gear Triple Crown Button Down Hoody – polyester, stretch, less resistant to biting insects, more comfortable in warm temperatures.
Base Layers
- Brynje Super-Thermo C-Shirt – minimalist polypropylene base layer for cool and cold conditions or warmer temperatures under an air-permeable shirt or shell, very light, rapid dry time, maximum air permeability.
- Finetrack Elemental L1 Long Sleeve Crew – polyester mesh base layer, very light and thin, very air permeable, hydrophobic, rapid dry time.
- Helly Hansen LIFA Long Sleeve Crew – polypropylene base layer, less air permeable, hydrophobic, light, rapid dry time.
Insulating Layers
- Senchi Designs Alpha 60 Hoody – active use, ultralight, air permeable, hydrophobic Polartec Alpha.
- Farpointe Alpha Cruiser Hoody – active use, ultralight, air permeable, hydrophobic Polartec Alpha, more consistent inventory.
- Enlightened Equipment Torrid Apex Hooded Jacket – inactive use in cool / wet weather, synthetic high loft insulation, 7d fabrics, not air permeable, high warmth-to-weight ratio.
- Feathered Friends EOS Down Hooded Jacket – inactive use in cool / dry weather, high fill power down insulation, not air permeable, higher warmth-to-weight ratio than synthetic high loft insulation.
Shell Layers
- REI Flash Jacket – full zip, hooded, pockets, air permeable, adjustable hem and hood.
- Gorewear R7 Shakedry Jacket – two-way front zipper, very high breathability, exposed waterproof membrane = no DWR required but subject to abrasion damage.
- Montbell Versalite Jacket – pit zips, ultralight fabrics, high breathability, somewhat fragile.
My Ensembles
Here are some examples of how I combine various layers for different use cases in three-season conditions.
1. Sunshine, warm temperatures, biting insects
2. Cooler temperatures, no wind or precipitation, no biting insects
3. Warmer temperatures with wind or precipitation
4. Heavy rain, strong winds, warmer temperatures
5. Cooler temperatures (no wind/rain, wind only, wind + rain)
Recommendations: Essential Layers
I’m in the fortunate position as an outdoor industry professional to have a steady influx of “gear to try” without having to shell out thousands of dollars trying to figure it all out. Over the past few years, I’ve made some changes to my layering systems, and the following represents my recommendations for what I think are essential layering pieces that represent a good balance of price, performance, form, function, versatility, and durability. Everyone will gravitate towards garments that appeal to their own aesthetic preferences and performance criteria – consider these as personal recommendations based on my experience, and don’t necessarily assume they will be optimal for your environment or use cases. Share with us in the forums below other layering options and ensembles that you find to be optimal for the use cases you experience.
Active Layers
Brynje of Norway makes both synthetic and merino wool fiber fishnet base layer apparel for outdoor adventures. Fishnet construction is more breathable, lighter, and faster-drying than conventional knits.
The Jolly Gear Triple Crown Button-Down is the only sun shirt integrating a full button-down front with a hood, offering adjustable ventilation rarely found in sun protective hiking apparel. Made from an 86% polyester, 14% spandex blend with antimicrobial and quick-drying properties, it includes zippered chest pockets, thumbholes, and a uniquely designed hood with a vent/hair hole and cinch cord. The body fabric is one of the highest air-permeable fabrics we've tested. Men's medium: 7.5 ounces (213 g) and up, depending on fabric choices.
Polartec Alpha Direct fleece hooded midlayer with fitted hood and paracord drawcord, constructed from open-knit synthetic fleece in 60, 90, and combination fabric weights, with manufacturer-listed medium weights from 3.8 to 5.3 oz (108–150 g) depending on selected fabric configuration.
Storm Layers
A full-featured, durable, air-permeable wind jacket.
- one of the lighter full-featured wind jackets on the market
- ventilation features - full zip, adjustable hood and hem
- durable, air-permeable fabric
- hand pockets
- not quite as light as the lightest 7d wind shirts available from cottage brands
A membrane-out rain jacket that requires no DWR for durable water-beading, with one of the highest breathability ratings of any jacket available.
- Intrinsic hydrophobic outer membrane requires no DWR
- 2-way zipper for ventilation
- very high MVTR (breathability)
- designed for slim fit over a base layer, size up 1 size for backpacking
- outer membrane is too fragile for sustained bushwhacking, scrambling, or shoulder strap wear when carrying an expedition-weight backpack
We recommend a synthetic insulated jacket for most conditions where weather is unpredictable, and the Torrid Apex is one of the best in terms of its warmth-to-weight ratio.
- available in 7d or 10d fabrics
- very high warmth-to-weight ratio for synthetic insulation
- synthetic insulation requires care, not as durable as down
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Discussion
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Mjh that’s true but only for absolute stinkiosity. For relative, it’s still interesting that Brynje smells more than Lifa to me but opposite probably for Tjaard
But is there an Absolute Stinkiosity Threshold that might come into play? I think that could be the case, based on . . . umm, things I’ve heard. Like where the Significant Other (well known to have an olfactory sense much more sensitive to objectionable odors than that of Oneself) has an Absolute Stinkiosity Threshold of 2.5, whereas Oneself has an AST of nearly 7. If it’s a logarithmic score, that’s a pretty incredible difference in detectable stinkiosity.
To come at the taint issue from another direction. I use a product called nuud rather than deodorants. It works by eliminating the bacteria that cause smell. I normally apply every 3 days, so on a longer hike will take an application worth in a cut off sealed straw. Having said that my preferred choice of next to skin is merino. When cool but wet I happily wear my macpac nitro as a base and find that covers a wide range of conditions if combined with windshirt (I stuff mine in shorts pocket which makes it a very quick to layer up or down) or rain shell. I only reach for brynje in freezing conditions but love it then. The challenge with lower half layering is getting on and off over footwear. For most Australian conditions I use a rain kilt over shorts and use gaiters if bushwhacking.
Looking to upgrade my rain shell and having a difficult time finding any shakedry shell, what is the recommended shell since it appears Gore Shakedry is no longer available ? Thanks
@Nick_Garcia: Seems like a potentially complicated question. I’m not an expert on all the WPB fabrics by any means, but there are lots of factors in play: Weight of fabric, degree of permeability, associated DWR treatments, PFAS use (though not for long, if I understand correctly), and more. I have been told by people who claim to know that Gore-Tex will be ditching almost all of their fabrics in the near future, largely because of the ‘forever chemical’ problem. (Which, IIUC, was the cause of the demise of Shakedry.) But they’ll allegedly be replacing those fabrics with new ones made from frog hair, unicorn oil, and phoenix feathers.
My own thought is that it’s all going to be even more of a “pick your poison” sort of affair. Weight v. wetting out v. water permeability v. dry time v. breathability v. price v. ventilation v. fair-trade labor practices v. personal biases, etc., etc.
Outdry for cool weather and lots of rain. EE Visp if you want a lighter jacket. Poncho or Packa for varied conditions, higher humidity, and better ventilation over a pack. Umbrella or umbrella hat for warm weather and low wind.
https://backpackinglight.com/rain-wind-jackets-testing-shell-game/
Wow, the R7 Shakedry was still available in all sizes up until recently and since I was on their mailing list received a 30% off coupon and bought a couple at $168 apiece, glad I did.
@MJ my “smell rating” is indeed self assessed. however, I don’t think that really matters, since I am comparing various garments/fabrics in the same way.
@Ryan, WBill or others using the R7, how has durability been for you?
wildsnow reviewed a Norrøna Jacket that combined GORE-TEX Active on the exposed parts, with Shakedry, which seemed like the perfect combo to me, but even that they said wasn’t durable enough.
https://wildsnow.com/34241/good-and-bad-of-an-experimental-touring-shell-from-norrona/
Duplicate
@Ryan, so you find it useful to bring both a windstorm and a WPB jacket on the same (short) trip?
I used to do so in the past, but more recently, at least for cool-cold trips, used only a WPB jacket.
My thought and experience, being that with the more breathable jackets, and especially with lots of venting:
If it’s calm and dry, I don’t need a shell. If there’s enough wind to warrant a wind shell, a highly vented WPB shell can vent enough heat and moisture to stay comfortable.
Part of that is that I’ve never thought to wear a windshell under a WPB shell. Doesn’t that reduce the total system breathability too much?
I haven’t had major durability problems with any rain jackets, perhaps because it is my least-commonly-used layer. People who wear ShakeDry as a windshirt have sometimes reported buying several while they were available. Now that Outdry is all that is left in the membrane-on-the-outside category, I don’t worry about durability at all (because Outdry is thicker/stronger/heavier than ShakeDry).
I think we all wish for a lighter Outdry, even if it might trade off some durability for lighter weight.
Many people make similar choices. I think the decision depends very much on ventilation (as you say), personal preference (weight vs comfort), and climate (frequent rain vs occasional rain).
Another factor is your active insulation. If it has some wind resistance (such as grid fleece), then a wind shell is much less important. Extremely permeable layers (Alpha Direct or Teijin Octa/Airmesh) benefit more from a wind shell.
Yet another factor is that “wind shells” need only a small amount of wind resistance to be effective, especially during high output activity. A sun shirt over AD/Airmesh is often all that it takes. If you were already carrying a sun shirt anyway, then you might never miss a wind shell. Rain gear is more comfortable in high wind than it is when calm.
Yes and no. WPB over wind shell is an edge case — an infrequent combination for specific conditions. Mark Twight proposed it when developing his seven-layer system for (almost) all weather conditions. He already recommends the WPB layer mostly for static use (or very cold weather), so the wind shell is mostly an extra layer of insulation that you may already have with you. His wind shells were DWR-coated and tightly woven, so they also added an extra layer of protection from water ingress and condensation.
In warm weather, the combination would certainly be too much. In cold, continuous, rain, then it could be a nice addition. It isn’t necessary, though. You can achieve a similar effect with an emergency poncho over a WPB, or with another layer of fleece (instead of the wind shell) under the WPB.
Thanks Bill, and apologies for the typos!
Funny, I haven’t thought about Marc Twight’s advice for years. 20± years ago, his book was the first time I heard anything else than the old “baselayer, fleece, WPB” system, and even the concept of looking at systems and real world use, like over layering a parka for breaks.
Re. Wind shells:
For example, on the last trip cold weather trip I did ( Hut-to Hut in March in Switzerland), I did bring a very thin sun shirt, to layer over my Brynje, either in the huts for warmth and modesty, or while skiing uphill if the weather turned hot.
So yes, if it becomes so hot that my WPB jacket unzipped over fishnet is too hot, I planned to use that.
But it seems like Ryan is advocating for a windshell with more wind resistance, in addition to a WPB jacket, and I was curious to hear more about the use of that system.
I am not Ryan, but here is my interpretation of what Ryan said in the article.
The wind layer has several possible functions when used underneath a rain layer:
1) It is an extra layer of insulation. It is not better than Alpha or some other insulator, but if you are carrying a wind layer then it is insulation that you have with you.
2) In prolonged rain people usually get wet. They often blame “leaks”, although I suspect that a more common culprit is condensation. Another hypothetical way for water to ingress is by overpowering the hydrostatic head of the membrane. This has been discussed on BPL in the past. The short version is that it depends on the wind and the size of the raindrops, which vary, as well as the specific membrane. There are many anecdotal “suspicions” of this kind of water ingress, especially with electrospun membranes. I have not been able to replicate it underneath a shower, but that does not mean that it can never happen.
Inside of a waterproof layer, you will get condensation for sure. Inside of a WPB, once the DWR wets out, then you will get condensation as well — possibly more than with a straight waterproof because the wet-out layer is cold.
In a perfect combination of weather and low output, you might stay dry inside of Outdry/ShakeDry that cannot wet out, but only if the outside vapor pressure is lower than inside, which requires some luck.
At minimum, it is nearly impossible to avoid avoid some condensation while active.
One way to deal with water under the rain layer is to wear insulation that works when damp, such as fleece (especially Alpha Direct or Octa/Airmesh which retain little moisture). You will still be damp, but you will be warm, and your body heat will eventually move the moisture away from you. Eventually, after the rain stops, your body heat will “cook” the system dry.
In warmer weather I like to wear just Brynje under a WPB, at least when I am not around other people.
Another way to deal with condensation or water ingress is to wear a DWR layer inside of your rain layer. With any luck, condensation that forms inside the rain shell will roll off of the wind shell. The wind shell may also provide some defense against rain driven through the rain layer (if such a thing really happens). So there is a possibility that a wind shell inside of a rain shell MIGHT BE dryer.
In any case, a wind shell won’t be any worse than wearing fleece under your rain shell.
3) One more advantage is that, when the rain stops, you can take off your rain shell and still be protected from wind. This is valuable if you are wearing only Brynje or AD/Octa under your shell(s).
All of these effects are subtle, and may occur only in specific conditions, which is probably why you don’t see the advice more often. Some people switch back and forth between wind and rain shells. Others wear only a rain shell and skip the wind shell completely. Still others wear two layers of rain gear in heavy conditions: WPB (for comfort and versatility) with a poncho (maybe an emergency poncho) over it for the cold/driven rain that Ryan describes.
TLDR: Wearing a two-shell system is an interesting alternative for cold/driven rain.
Choose what you like for the conditions you face, and be aware that other combinations may be possible.
something that happens to me is that I wear too much and sweat. Then, even if I have breathability the sweat will overwhelm it
so, take everything off except lightweight base layer and rain jacket
even then I might sweat but at least only the base layer gets wet, and if I stop, it’ll dry in an hour or so
Excellent write up! I was hiking in Northern Maine for three weeks in November (AT SoBo hike) and this type of layering worked exceptionally well for me. I found the Brynje / REI Flash combo indispensable. Another modulating factor I found was hat on / off and over / above ears. Zip up / down, hood on / off. As I hiked up / down, and rest, I found myself making many subtle changes to stay actively cool/warm and dry. Addition of the Versalite over the whole thing while above treeline in poor conditions was awesome. I found the REI flash material pilled up under the rub points with my pack – when I went to replace it this week I sadly found it had been discontinued. I ended up replacing it with a Janji Zephyrunner – no experience with it yet, but seems functionally similar (breathability and pockets) although a smidge heavier. Any other suggestions on a good replacement for the Flash?
Ryan, This layering concept is very helpful! REI no longer sells the Flash jacket, what would you recommend in its place that would be similarly breathable?
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