Base Layer

Wayne, I wear wool all year long and have done so for years now. Wool is not just for cold weather. In my opinion, my Ibex wool polo shirts perform better than cotton in the heat. My 3 season base layer is a Smartwool Shadow Hoody. My choice in the winter is the Ibex Hooded Shak. See my reviews on both and also check out this BPL article. As for discounted merino wool, this thread may help. I’m happy with Ibex and most of my wool comes from them.

Wayne: I used to wear those Nike Dry-Fit Shirts as a base layer, but I switched to merino wool last summer. My Icebreaker Oasis LS Crew performed very well, even above 77 degree Fahrenheit. And it's black! It cooled my torso at day and warmed me at night (DriDucks were the only other clothing I brought, and I wore both inside my ArcEdge). I found that merino top performed a lot better than the synthetic running tight that covered my legs.
Just try it, you won't regret it!

Icebreaker is an NZ company. I chose it because Smartwool isn't available in Europe. I guess they perform equally well.

Wayne:

Given all the rave reviews about wool, it may well be worth a try. But wool isn't for everyone, so you might want to buy just one tee shirt and give it a try — before re-orienting your wardrobe.

A few months ago, I bought a Smartwool l/s merino wool tee. Even after repeated washing and wearing, the thing still feels itchy at times. But even when it isn't feeling noticeably itchy, it still feels less comfortable to me than my Campmor Duofold synthetics.

This is not to bad mouth wool, but simply to emphasize testing before switching. And one shouldn't dismiss outright the advantages of synthetics; namely, lighter weight and quicker drying time.

Wayne,

I'm a merino convert as well. I don't have the most sensitive skin but I do percieve a difference in Smartwool vs. even the decent REI MTS brand and my Smartwool stuff is much more comfortable than the bargain merino shirts and socks I've tried. I've also found Smartwool's merino blend socks to be more durable than REI's versions. I do think that the increased price you pay for Smartwool products does translate into a better engineered product made from superior materials. I have no experience with similarly-priced products from Ibex or Patagonia.

As for application, what you have will probably work just fine so there's no definite need to switch. Merino wool offers benefits in terms of durability and odor control over synthetics but its not a must-buy. Merino will not wick as quickly or dry as quickly as most comparable synthetic garments but will perform much better than pure silk garments. A microweight or lightweight merino top is fine for summer temps; I've worn mine in 100 degree heat on the humid A/T and in the dry Grand Canyon and been comfortable.

Ben makes a great point about testing gear out. I tried an REI Merino Wool long-sleeve shirt last year and it itched intensely no matter how much I washed it. This year, I tried a Smartwool microweight long-sleeve crew neck and found only a tiny hint of itch at first, and this has mostly gone away. My synthetics are still more comfortable to the touch when clean and dry, but once I begin sweating, the merino wool quickly gains an advantage in cooler weather. For summer, I suspect I'll still prefer synthetics, but I intend to try a merino wool short-sleeve this spring.

I use loose-fitting supplex nylon as my base layer and then put some sort of insulation on top if I get cold (a vest or jacket of either polarguard or fleece). I sleep in the same shirt and pants than I wear during the day. I even do this while at home so I don't have to bother with washing sheets. Supplex is quite stink-reistant, very comfortable (if you don't have lots of buttons and pockets and other junk, which my clothes don't since they are hand-made), and dries very quickly if it gets wet from rain or perspiration.

I really don't understand the reasoning behind tight-fitting base layers in 3-season conditions. They are certainly warmer than supplex (a dubious advantage in the summer) but not nearly so warm as a typical jacket, and they are much more troublesome to remove than a jacket when it gets warm. Also, wicking is greatly overrated in 3-season hiking. If the moisture is from perspiration, then you want the water to stay on your skin to help cool you down. Otherwise, you'll just sweat some more. The only time I can see that wicking might be useful is if the garment gets sopping wet on a cold day, but you want to continue wearing it so as to dry it out with body heat. In that case, a wicking fabric slows down the loss of body heat as compared with a non-wicking fabric like supplex. A better approach is to avoid getting the garment wet in the first place.

Russell wrote above, "I've worn mine in 100 degree heat on the humid A/T… and been comfortable."

In the scenario you described, I can't imagine being comfortable even if hiking nekkid, never mind wearing wool — not that I've actually hiked nekkid. :)

Ben,

Comfortable being a relative term. I do most of my hiking on the AT and trails very much like it. I'm not much, if any, more comfortable in clothing made of other materials. A little heat won't keep me out of the kitchen!

I use wool almost all of the time, either Ibex, Smartwool or Icebreaker. I think the most important thing for base layers is get as fine a wool as possible, my favorite at the moment is an IBEX 17 micron shirt, I have worn it some fairly warm situations and it has worked for me. Quick drying is a must in my view and the finer wool tops are certainly that.

I could be wrong but I think Ibex is the only top tier manufacturer using 17.5 micron merino. I have an Ibex polo made of it that I love. I'm wearing it in my avatar picture.

Frank,

Sweat that does not evaporate doesn't cool the body very well. This is because evaporating a mass of water carries away much more heat than simply warming it up X degrees. Poly base layers work even in warm (but not humid) climates because they don't hold water as much as other natural and synthetic fabrics, and they move water along their surface, increasing the surface area for evaporation. A tight fitting layer allows for this mechanism better than a losse one. I wear long sleeve poly cycling jersies cycling in Arizona in the summer because they are cooler than even bare skin and keep the sun off. I modify my jersies with pit zips as bulk flow of air in that area works better than the fabric alone and integrates with pit zips on my wind jacket.

Supplex clothes weigh as much as a light poly base and a light windshirt, which can cover a wider temperature range. That said, I also like loose supplex wear for hiking in the desert as it is more durable than knitted poly base layers or light wind shirts. In a humid climate nothing is comfortable for very long, IME.

wayne k—i used to wear silk—it feels very warm when first put on (bearing in mind how light and thin it seems) however after 1 days use it i found it less warm—-unscientific guess—the bodies natural oils polluted the silk and stopped it insulating so well

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advantages weighs little —dry easily after washing—packs tiny—disadvantages—not durable

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switched to icebreaker now—-i do not buy the lightest weight 190gms/m? as i figure that with a bit of wear and washing the slightly heavier wieghts will thin down—-ps body oil does not seem to affect merino—-regards barry

I think an arbitrary definition of terms will help to possibly (smile) build a consensus on the best base layer. Without any clothing assistance or sweating, our body’s thermoregulation capabilities will keep out core temp at 98.6 over the approximate ambient temperature range of 77 – 82.4 when at rest. As our activity level goes up, the thermo-neutral range also goes up. Conversely, it goes down as we rest or sleep.

Let’s call being thermo-neutral, Range B. Needing warmth, Range C and needing cooling (sweating) Range A. The performance fabrics such as Merino wool, synthetics, or silk are near optimal for temp Ranges B and C. Merino wool provides a moisture buffering capability so that the temperature regulation is more leveled for Ranges B and C. Light colored and loosely fitting nylon or gasp-cotton are optimal for Range A.

Performance fabrics (polypropylene, polyester, wool, and to a lesser degree silk) keep the body dry during vigorous athletic activities. Keeping the body dry, especially during cold weather backpacking, ensures that the wearer does not lose heat unnecessarily by having wet skin. In the case of performance fabrics worn in hot climates, how a fabric feels to the wearer is one of the most obvious attributes that the BPL forum posters sense. Performance fabrics help to ensure that the backpacker does not start to feel clammy because, in general, “dry feels better”, but it doesn’t cool you as effectively as having wet skin.

The optimum form of sweat utilization is the evaporation of moisture directly from the skin to be released as water vapor. This is true because most of the heat energy needed to evaporate the moisture is extracted from the body causing body temperature to drop. Only via the evaporation of liquids can the body efficiently cool itself at high physical loads. Also, the heat flow from the skin through the clothing can be considerably greater when the clothing is wet, since water decreases the thermal insulation of clothing. This happens because water has a greater thermal conductivity than air. Consequently even a loosely fitting garment will touch the skin in places and if it is wet (Supplex or cotton) it will very rapidly conduct heat to the atmosphere.

If one can wear clothing next to the skin that does not pick up any moisture, but rather passes it through to a layer away from the skin, heat loss will be reduced. Most performance fabrics have low absorbency as well as excellent wicking properties that make them more comfortable to wear, since perspiration can travel to the surface of the fabric where it evaporates.

Neil:

I meant loose non-wicking clothes allow the water from perspiration to stay on the skin WHILE IT EVAPORATES, thereby cooling the body. The problem I see with knit and wicking polyester or wool garments is that the evaporation takes place at the outer surface of the garment, but this cooling doesn't cool the body very much because the garment acts as an insulator, so the body just produces more sweat, which wastes water and salt and fouls the garment besides. Yes, if you open enough pit zips and whatnot, you get evaporation at the skin, but this is the same as if you were wearing something loose.

In cold weather, evaporating at some distance from the skin is thought to be an advantage, but it can also be a disadvantage, at least if you tend to frequently work up a sweat in cold weather while walking uphill or otherwise exerting yourself. Once a garment is sweat-soaked, there is the risk of mild hypothermia from flash evaporative cooling when you take a rest break. With a loose shirt under a jacket, you just take off the jacket and then it should be easy to stay cool enough to avoid sweating. Removing a base layer that is under a wind shell is normally much more of a hassle than removing a jacket and tends not to get done, so the base layer eventually gets sweat-soaked. Perhaps it is possible to avoid this with the correct choice and use of gear. My own experience is that even the thinnest wool base layer causes me to frequently sweat when I exert myself, even at sub-freezing temperatures. So I have to stop and remove the base layer, which is such a nuisance compared to removing a jacket that I eventually stopped using insulating base layers altogether. And then I began thinking about the whole base layer concept and concluded that insulating base layers simply don't make sense for most conditions.

Incidentally, my supplex shirt weighs 210 grams, which is just slightly more than what my old Ibex zip-t base layer weighed. Yes, I know that some supplex shirts weigh twice this, due to unnecessary pockets and other doo-dads.

Brynje polypropylene fishnet is the perfect insulating base layer, since it allows evaporation to occur on the skin, but yet provides good insulation when not perspiring (if used under a windshirt), and never absorbs much water. A Brynje fishnet shirt was the last insulating base layer I ever used, and it is truly remarkable stuff. Unfortunately, polypropylene fishnet picks up smells and these smells are hard to remove by hand washing, which is why I gave up on the fishnet.

I agree that nothing works well in hot humid weather, but loose supplex is probably the best choice (assuming cotton and hemp are ruled out) if you are forced to wear something, either for sun protection or for social reasons. Very loose cut, so you get plenty of breezes.

Frank,
Brynje does make a merino shirt with the fishnet lining if the stink from polypro bothers you. I haven't tried it myself, and I don't know where to buy it but here's a link with more info if you are interested.

http://www.brynje.no/public/upload/files/z_pr_materiell_17_Arctic_brosjyren_engelsk_alle_sider.pdf

I also own a 20F arc-alpinist and this winter tried to see how far I could take it down in temps. In near zero temps, I wore a wool base on my upper body and all synthetics on the legs. Both worked out just fine. Unsuprisingly, the weak point in the system was always the head/neck area. The piece that really made all the difference was my smartwool shadow hoody. Forget the material, the nice thing was having solid fabric from my waist to the top of my head, no gaps or drafts. For the arc bags, whatever your upper body base layer is made of, go with the hoody.

Frank,

We're pretty much in agreement then. Good deal on the no-frills supplex wear. I suspect your metabolism is different than mine if you find it comfortable as a base layer at cooler temps. My experience with certain textured polyesters is that they do cool better than bare skin particularly when they are light colored and block the heat effect of direct sun. They prevent sweat from dripping under gravity where it does no good except dehydrate. I've successfully used fishnet in the past and would probably try it again if it were easier to buy. I prefer merino for socks where sweat absorption is a bonus. I find silver treated polyester does a good job of keeping the stink down. Some of the polyester wind wear is just as comfortable as supplex but lighter and more fragile, and hard to find in the lighter colors needed for hot desert hiking. Ultimately everyone's body is a law of physics unto itself, and there's no arguing with what works on an individual basis.

Thanks for the comments and advice. Looks like silk is probably not what I'm looking for. I already have a pair of smartwool socks I like a lot. I'll probably check out what REI has in Smartwool/Ibex/Icebreaker, maybe try one on in the store. Then I've got to do some price shopping. I see the Ibex sale, but they don't have exactly what I want. Sometimes, by the time you factor in the REI rebate and return policy and shipping costs from a mail order outlet, REI turns out to be the best deal. Especially when you consider the expectation that money saved on gear should be spent on other family expenses whereas REI rebates are spent on MORE GEAR!

Now I've got to decide: lightweight (what I currently need) or midweight (which will wear to lightweight soon enough)? And hoodies? Hmmm.

James:

That link is for a shirt with polypropylene fishnet inner layer and 70% merino wool/30% polyester solid outer layer. Meraklon is Bryjne's proprietary brand of polypropylene. As with the Brynje fishnet only shirt, this is great stuff, performance-wise at least for people in very cold climates (I never come close to needing something so warm), but it will pick up stink. The purpose of the merino wool is not stink-avoidance, but rather to absorb moisture so it doesn't condense in the outer insulating layers. Later, such as during rest breaks, this moisture can be evaporated and vented out the neck opening.

Incidentally, for those for whom the idea of not wearing a knitted base layer seems strange, this is how the Eskimos used to dress. Namely, they had a fairly loose fur jacket (with the fur turned inwards) and nothing underneath. When they started to perspire, they just opened the neck and bottom so as to let some air in to evaporate the perspiration and cool things down. When the perspiration stopped, they closed the neck and bottom back up. This is essentially what I do, though in much more temperate conditions. The supplex shirt acts primarily as a windbreaker, which is all I need when I'm working hard. When not working hard, I just pull on my Patagonia Micropuff. I don't think my metabolism is particularly high. Rather, it tends to alternate between low and high. When on low, I need lots and lots of insulation in cold weather, much more than a base layer could provide. When on high, I need nothing more than the supplex shirt (this has a zip-t neck, so it acts like a windbreaker) plus mittens and hat. So I wear the Micropuff until my metabolism switches to high, then I take it off. The result is I don't perspire much in cool or cold weather. No perspiration, no need to wick.

Does anybody know of an alternative to the polypro Brynje.ie an open mesh layer that doesn´t hold odors.