10 January 2019
About Wool in General and our Wool in Particular
If there was something better than wool, we would not be doing this!
On this page we refer to seriously high quality wool, although much of the information is also true of wool in general. Please click here for specific information about WeatherWool Fabrics.
QUICK POINT: Sheep can tolerate varied and extreme weather, even on the same day. And like people, sheep need to keep their body temperature steady, regardless of environmental conditions. The body temperature of a sheep is a little warmer than that of a human, and the wool that works in synergy with the sheep will do the same for us, if we treat it right. WeatherWool is about letting the very best wool do what Nature made it to do. It may sound strange, but wool does what we (a sheep, really) need it to do in a variety of different situations. Wool is a living fabric ... an insanely sophisticated material that has evolved to do exactly what we ask it to do. We let wool be wool!
There is no garment or material that is perfect for all conditions, but the best wool garments come closer than anything else ... because ... sorry to come back to this again ... that is what Nature created wool to do. And Nature is not only the most sophisticated designer and engineer, but also the most ruthless of testers. Wool works with the body's own regulatory systems ... and clothing that does not work with your body's own systems is a hindrance.
If you're headed off to some remote location where you might have to deal with cold, heat, rain, snow, sleet, wind, sun, rough terrain, fire, even hostiles, you cannot beat the performance of wool. In addition, wool is ultra-quiet, non-reflective and extremely durable. Wool is also relatively resistant to fire and arcing, and is considered by medical professionals to be hypoallergenic. And serious wool is also extremely comfortable and luxurious.
There are important factors beside pure performance. People prefer natural products to synthetics. Who likes formica more than wood? Vinyl more than leather? Cement more than stone? Nobody loves their synthetic clothing. But people love their serious woolens. The best natural products are a pleasure to have and to wear, year after year, even if you don't have to face extreme conditions.
There is an understandable tendency for people to assume that modern technology can improve upon nature. Air travel, the internet, cellphones, artificial knees ... awesome stuff!! BUT! The most sophisticated man-made products are tinker-toys compared to the workings of every single cell in our bodies. And dealing with their environment is something every living thing must do. Sheep can thrive in the most intense winter conditions. And they can handle serious heat too. Wild sheep living at 20,000 feet in Asia often have serious heat and serious cold in one day, and their wool protects them from both extremes. Some of the sheep that grow our wool also thrive in places (New Mexico, for example) where it can be cold and hot in the same day. And WeatherWool Fabric enables us to do the same.
No synthetic fiber is anywhere near as sophisticated -- as ‘hi-tech’ -- as wool.
And natural designs are not frivolous. Every element of a wool fiber enhances the ability of the fiber to protect the sheep. And all this exquisite functional complexity is tucked into a single fiber of wool that is, in the case of WeatherWool, 21 millionths of a meter thick. Thanks to the American Sheep Institute for the diagram.
Below is another diagram from the American Sheep Institute. Not only are synthetic clothes energy intensive, but the materials used to make some of them, such as polyester "fleece" (!!!???) actually come from oil wells.
The marketing experts always say to start off with the positives. But I'll go contrary. Synthetic fabrics have three advantages over wool. Weight, bulk and cost. Those factors are important, and if they are the only ones you care about, go synthetic. But there are a lot of other factors to consider ... the most important question to answer, in my opinion, is ... What will keep you safe and comfortable over the widest range of conditions? If overall comfort level -- overall performance -- is the deciding factor, then wool is tops. Interesting thing ... there are companies famous for their synthetic outerwear that now recommend and sell wool base layers. They are saying that after extensive research, they've determined merino wool makes the best base layers. And our Rambouillet Merino Wool makes the best outer layers too.
Rambouillet is the French variant of the more well-known Spanish Merino. There really are few hard and fast rules, and there are many variables. In general, Rambouillet fibers are a little thicker than typical Merino, and thickness helps to strengthen the fiber, making it more durable. Rambouillet Sheep have also been bred to have longer fiber than Merino, and longer fibers makes for stronger and more durable fabric. Wool can be extremely tough and durable and there are many different types and grades of wool used for different purposes. The thickest, toughest wool can be used for rugs that will stand up to years and even decades of use. Some of the world's most beautiful and functional rugs are made of wool. Casinos worldwide are carpeted with wool because cigarette butts cannot make wool burn. Wool is seeing more and more use in high-end home and commercial settings because modern, air-tight construction techniques prevent dissipation of unpleasant and even harmful odors from paint and other building materials.
This is why sheep can ignore all kinds of weather!
Wool will remove these chemicals from the air and make the indoor environment more comfortable. This odor-absorption trait also makes wool valuable for clothing because wool can be worn for extended periods without becoming odorous ... that is, wool will adsorb, internally, the compounds that create the smell people recognize as body odor.
Wool used to manufacture clothing must be selected according to the performance characteristics desired for the particular garment. The requirements for woolen outerwear are stringent, and WeatherWool’s requirements even more so. Our wool must perform in a wide range of weather conditions. That's what wool does anyway, so no problem there. However, it also has to be very tough in order to stand up to the rigors of outdoor work and recreation. The toughest woolen fibers are the thickest. But thicker fibers are uncomfortable on the skin. Wool that is great for rugs would be extremely uncomfortable in a shirt. The thickest fibers are also the stiffest, and when the end of a thick wool fiber contacts the skin, it tends to jab the skin instead of bend. The thinnest wool fibers will bend when in contact with the skin, resulting in a wonderfully soft and silky feel. Some of the very finest men's suits are pure wool. Even very light, high-end summer suits are made with wool. However, other things being equal, the thinnest fibers are the weakest, both in tensile strength and in abrasion resistance.
WeatherWool’s fabric must be not only tough and weather-resistant, but also extremely comfortable to wear. Other makers of woolen outerwear use coarser wool than we do. Cool and cold-weather outerwear mostly does not touch the skin, and so thicker, scratchier and cheaper wool is acceptable to the other guys. But WeatherWool is about extreme performance in severe conditions as well as extreme comfort in all conditions. If we used typical outerwear fiber, we would need to use a liner fabric in places where clothing tends to touch the skin, such as the neck and wrist. But if you spend a lot of time outdoors, you will get rained on. And we require WeatherWool to be relatively impervious to rain. Wool does a good job in the rain, but the liners used by other wool makers are a disaster in wet weather. The liner materials, synthetic acetate usually, readily get wet, and constant contact with a soaked liner results in wool wicking water from the liner. And even more unacceptable is that the liner will be essentially just a wet rag on the back of your neck and at your wrists ... two places where you can lose a lot of heat in a hurry. And chilling the blood flowing to your brain and your hands can be disastrous.
A wool fiber, magnified. The scales (the cuticle) repel water. But, water vapor can infiltrate the fiber thru the spaces between the scales, and the interior of the fiber does adsorb and react with water ... and heat is released when that happens!! Also, wool will adsorb the vapors of perspiration, preventing sweat from forming in the first place, and just as importantly trapping the heat contained in the vapor and slowly releasing that heat when it is needed. The way wool handles water and perspiration is so key, and so interesting, that we have a separate page, Wool and Water.
So, how to make a garment that is tough and weather-resistant but still soft and comfortable on the skin? We chose Rambouillet Merino because Rambouillet fibers are longer and slightly thicker than Spanish and Australian and New Zealand Merino. (Incidentally, there are some who claim Merino was first developed in the USA.) Our Rambouillet fibers are about 21 microns (a micron is a millionth of a meter) in thickness, whereas the traditional Merino is about 19 microns. The Rambouillet fiber is thin enough to be completely comfortable against face, neck and wrists (we even make WeatherWool Scarves), but the extra thickness makes it considerably tougher than 19-micron Merino. However, at WeatherWool our philosophy is to make the best we can figure out how to make. And another way to make fabric stronger and more durable and softer all at the same time is to use longer fibers. So, WeatherWool is made with the longest Rambouillet fiber that the spinning machines can handle. That is, we have purchased our raw wool from growers whose flocks simply have extremely long fiber. And even then, we use only a fraction of the fleece. On any sheep, the best fibers are found on the sheep's back, the sides of the body and the top of the head and neck. WeatherWool Fabric is made from only the best fibers of each fleece, and only from the Rambouillet flocks with the best fleeces to begin with. It won't surprise anyone that the finest woolens can only be made from the most select wool. And that the most select wool is also the most expensive.
These sheep at the Jewell Ranch in Colorado have just been ‘crutched’ ... the wool has been sheared from their lower legs and disposed of so that it does not contaminate the higher-quality parts of the fleece that we buy.
When raw wool is prepared for sale, part of the process for high-quality wool involves laboratory testing across about 20 different parameters, including:
- Length of fiber ... the longer the fiber, the softer the fabric and the stronger the yarn. However, fibers longer than three inches (7.6 cm) are more difficult to scour (clean) prior to spinning ... and fibers longer than 4 inches (10.2 cm) are a problem for the spinning woolen yarn for weaving
- Thickness of fiber ... the ticker, the stronger, but also, the itchier. We must find a balance! And actually, this "thicker is itchier" concept applies across materials, whether natural or synthetic. Thinner fibers are more comfortable on the skin. Our fiber averages a little less than 21 microns (millionths of a meter) thick. A human hair is typically about 50 microns.
- Tensile strength ... we test to make sure our fiber is uniformly strong.Tensile strength is highly important to us because this is another characteristic that is very much reflected in the fabric, and we need strong fabric.
- Presence and Placement of weak spots ... weak spots are mostly caused by the annual cycles of the ewe's of pregnancy and lactation. We look for the weak spots in the fiber to be near the ends, so that if a fiber breaks, the break will be near the end, where it is less noticeable
- Crimp ... (kinkiness) greater crimp yields warmer fabric. Also crimp enables stretch and recovery
- Presence of paint ... paint is bad!
- Color ... Someday we will seek colored yarns for specific purposes. But in general, we need fiber that does not have any natural color so that we can control the color of the final product
For all these factors and even a few others. Our wool grades out on top.
Less appreciated is something like the presence of polypropylene (from feedbags, tarps, etc.). If there is any polypropylene anywhere near the sheep, it will inevitably find its way into the fleece, where it cannot be effectively separated. Polypro fibers will mix with the wool and ultimately be woven into fabric, where they will create weak and unsightly spots. (Please click for an unfortunate story about polypro in wool fabric.) The only way to avoid this problem is to buy from a grower that does not permit polypro anywhere near the flock. This step takes special effort because polypro is a very popular material for feedbags, and polypro tarps are widespread. Avoiding polypro raises costs for the ranchers. More information about these factors on our Fabric page.
Weather-resistance can also be enhanced by the employment of the finer weaving techniques. WeatherWool is woven on a Jacquard Loom, which creates a thicker fabric, a truly 3-dimensional fabric that sheds rain and wind and insulates much better than the usual, far cheaper flat weave. Our Lynx Pattern can only be woven on a Jacquard Loom, which is capable of weaving yarns of several different colors and bringing whichever color is desired to the surface of the fabric at any given point, thereby creating complex patterns such as Lynx. Solid colors and simple patterns such as stripes and checks can be achieved with a standard loom. For WeatherWool Fabric, however, even our solid colors are woven on the much more expensive Jacquard loom because we require the enhanced performance of the 3-dimensional fabric. Part of the finishing process for WeatherWool fabric is known as napping. Among other things, our napping process tightens and softens our wool, and creates a directionality to the fabric that helps channel rain off our garments. Wool naturally resists rain quite well, and we use absolutely ZERO cotton in our fabric and our thread, so WeatherWool will resist rain better than other woolens. And our napping process increases the rain resistance even more. Also, both the napping and the 3-dimensional weave reduce the reflectivity of our Fabric.
Here are some examples from our recent experiences with our WeatherWool test and production garments, and from our days wearing woolens made by others.
* In December of 2017, I took a quick swim in an icy river, dressed in WeatherWool, then simply went about enjoying a nice afternoon in the winter woods. You can see this on Youtube.
* In November of 2012 I went out for a morning hunt. Temperature was about 42F/5C. A pretty good rain was falling for the first hour, and then a torrential rain for the next 90 minutes. Really great conditions to get hypothermia without adequate protection. I wore the very first prototype FullWeight WeatherWool All Around Jacket and a prototype Hood (a single-layer hood, not the Double Hood we offer for sale) in Lynx Pattern, and FullWeight WeatherWool Pants in Solid Drab Color. For a base layer I just wore regular briefs and a true summerweight merino base layer from Icebreaker on top. I also wore a WeatherWool FullWeight Boonie Hat in Lynx Pattern under my Hood. Even with all that rain, my head never felt even damp. My legs also felt almost no moisture, but I was on my feet the entire outing. My shoulders felt some dampness, and my arms. Only my hands really felt the conditions, because most of the time I was not wearing gloves. I continued to wear the same wool when we stopped for lunch, and well into the afternoon after I'd arrived back home and did some office work. We’ve made design changes since that day in 2012 (such as adding flaps over our pockets to keep out the rain) but I am still wearing that same proto, which has since seen a lot of use, including an entire day in the rain with temperature just above freezing.
* I've been wearing WeatherWool, of course, since we made our first prototypes in the beginning of 2012, although it wasn't until late 2012 that we had our FullWeight Fabric right. Since then, in temperatures as low as 20F/-7C, I've been wearing my WeatherWool All Around Jacket over a single layer of Woolpower or, if it is on the warm side, Icebreaker (you can read about these brands at Alex Outdoors, our sister company) on top. If I'm hiking or just planning a half-day outing, no need for long johns even at the coolest of this temperature range. And this outfit will keep me comfortable outdoors, in the car and often for an hour or several hours after I get home. One recent hunt I did wear long johns because I planned to stay out all day (temperature right around freezing) but I was tagged out by 10AM and would have been fine without the base layer over my legs. Sorry to repeat, but because WeatherWool is made with Rambouillet Merino, which is very fine wool, it is comfortable on bare skin, so no problem skipping the long johns.
* As an exhibitor at many shows over the years, I've worn FullWeight WeatherWool all day long and was completely comfortable. More recently I've worn WeatherWool MidWeight Pants at the shows. In both cases, many people commented that I must be over-warm in a complete wool outfit at room temperature, but comfortably wearing the same garments in both sub-freezing and room-temperature is what WeatherWool is about.
* Doing presentations to the US Air Military in January in Alaska, I was comfortable indoors at typical room temperatures and outdoors in temps around 0F/-18C ... I did put on a Hat when I went outside, but otherwise made no changes. I wore our MidWeight Pants, a wool base layer on top, and a FullWeight ShirtJac. This is what I normally wear when doing shows, also.
* I once had a great call from an Alaskan Guide. He told me how he was meeting a group coming in by plane for a 27-day hunt. His own clothing was supposed to be on the plane with his clients, but it wasn't. He had no choice but to take his clients out wearing only the clothing he happened to have on at the time, which was wool. Since then, he said, he just wears his wool all the time and he doesn't care what the weather does.
People have been wearing wool and breeding sheep for thousands of years. Not surprisingly, there are many different types and grades of wool, and dozens of ways of turning wool into yarn, fabric and clothing. Different approaches result in garments with different properties. Some approaches cost less than others. Less expensive woolens can be made from shorter wool fibers (weaker and itchier); thicker wool fibers (itchier), stamped-on patterns (won't last); non-virgin wool (can mean lots of different things); dry-clean-only wool (dry-cleaning stinks and can strip the last of the wool's natural lanolin if done often) and even wool that is recycled from other garments, and glued back together (just what it sounds like!). The steps that yield the best clothing are generally also the most expensive.
What about modern synthetics? How do they stack up against wool?
* The first thing to notice is that a lot of the time they call the synthetic stuff ‘fleece’. And lately ‘microfleece’. Sorry. Fleece comes from sheep! The fact the synthetics guys have corrupted the word ‘fleece’ is telling. Next maybe they'll start saying ‘genuine fleece’.
* I know there are companies saying their poly- or micro- whatever (they usually don't say exactly what the stuff is!?) garments are waterproof, windproof and breathable? I certainly haven't tried them all, but the ones I have tried that were waterproof and windproof were nowhere near breathable. And I wound up getting wet from the inside, from sweat, even in cold weather, and THAT is a situation to be avoided. We talk to a lot of people in the outdoor fields, and I have never spoken to anyone who could show me windproof, waterproof and breathable.
* GORE-TEX®?? I've certainly worn that stuff. Here's one thing I don't like about it. The GORE-TEX® outer layer is designed to love moisture – that's how it pulls moisture from inside the garment to the outside. But because the outside loves moisture, when it's not raining, but still drippy and humid, the GORE-TEX® outer layer is soaked for no good reason. And when it's wet, it pulls heat from you, and you can wind up feeling cold even when it isn't really cold. And if it is cold and you are exerting yourself, sweat can condense on the inside of your GORE-TEX® shell. Very bad news. None of these problems exist with wool -- snow, wet brush, light rain, drippy woods and very often heavy rain and sleet, can be completely ignored. And wool just breathes waaaay better. Of course, the main reason to wear GORE-TEX® is for protection from rain and water. Good wool provides significant protection from rain without the disadvantages of GORE-TEX.
* Fire? That's not something that comes up often. But if it ever does happen, a petroleum-based synthetic product tends to melt onto your skin. This is a big factor for the Military. Wool is much better behaved. Wool can provide a huge advantage to those who work with electricity, or in situations where static electric can be a problem. Because wool naturally absorbs moisture from the air, it helps to suppress static charges. Embers popping off a campfire will melt right thru the synthetics. An ember will self-extinguish on wool. This is an extremely serious subject, and we will be adding more information. Wool is not fireproof, but it is more burn-resistant than the synthetics, and far more resistant than human skin. We have been told that WeatherWool easily passed US Military flame-resistance testing.
* Scent resistance, scent adsorption, scent control? Wool resists odors very well. Lanolin is a natural anti-bacterial. Another reason wool resists odor is because of the way it handles the moisture that bacteria need to do their thing ... wool sheds water and adsorbs vapor ... the behavior of wool is different than other materials, and this difference inhibits bacterial activity because wool does not let water linger on its surface. It also tends to adsorb what odor might be produced. Lately, of course, clothes that neutralize odor are getting a lot of attention. Field & Stream magazine has more than once published the results of some very interesting tests on the subject. In one test they used a police dog trained to detect the presence of humans, and had a guy hide from the dog. The dog had no trouble detecting the man's presence despite use of the best scent control available. Total scent control vs no scent control at all did not even matter ... the dog found the person in a matter of seconds -- as if whatever it was the dog was scenting was not masked by a scent-control shower, two layers of carbon clothing, scent control spray and scent-control chewing gum. Whatever you wear, remember the wind direction! This is a very interesting subject to me, and I read about it whenever I come across something. I believe there are a lot of questions that are still unanswered. I wore some of the very first Scent-Lok suits in the early 1990s, and, based on close encounters with whitetail deer, I'm convinced they reduced my scent enormously. It also seems to me that some of the anti-scent sprays are well worth considering, but I haven't done any experiments myself. There is also another aspect of scent/odor resistance that is very important, particularly for base layers, but for outerwear as well. If you wear synthetics day after day, even synthetic outerwear, the synthetics will become smelly even to a human nose. Not an issue with wool. We got an amusing testimonial from a very careful and analytical customer who is a serious outdoorsman. He told us one of the things he appreciates is that our garments do not absorb the odors of the dairy barns and ranches where he works. Wool is much better than cotton at controlling odor, and it is wildly better than polyester.
* Noise? At this point, everybody knows nothing is quieter than wool.
* Camouflage? Wool does not reflect light, and its soft, natural, fuzzy texture blends in. The uneven surface, the scales, of wool fibers prevent woolen fabric from reflecting light well. Wool accepts many dye colors readily, although it tends to resist blaze orange. Wool in solid colors, such as our Drab, also works very well in the field but does not stand out in town. And our Lynx Pattern is great camo but is not perceived as a hunting pattern. Debby has been referring to LYNX as camo-camo, meaning that people who think in terms of camo will immediately realize that Lynx is very effective and versatile camouflage. However, people who do not have that frame of reference, such as the general crowd at a shopping mall, will see Lynx as just a really attractive pattern. Our wool and dyes are UV neutral. Also …. think of a deer – it's not wearing a real camo pattern, but tends to be invisible unless moving or silhouetted. Same with wool.
What if you're not going to be 50 miles from civilization? Most of us can get by most of the time without really NEEDING the best clothing. But no matter what you are doing, the best gear still enhances any activity, and it can make the difference. Another thing is that a lot of us get a little sentimental about our gear. Favorite hat, favorite boots, favorite jacket ... it's nice to know that you're going to be wearing your favorite clothes year after year and it doesn't matter all that much what the weather is doing.
It's very common for outdoors people to buy new clothes every couple of years, because they are always looking for something better. As a buddy of mine says, “Why rent your clothes when you can buy them?” Buy the best stuff and that's that. Another very apt perspective was provided to us by our Advisor Tom Brown III, a professional outdoorsman and instructor. As he put it in a testimonial he provided to us, clothes are tools, and he wants the best tools.
A while back I spoke with a fellow who spends a lot of time as an outdoors professional in Montana. Over the years I've had probably hundreds of similar calls. He told me he's invested in plenty of the new, “technical” clothing, and after wearing it afield, he doesn't want to know about anything but wool, although he does pack a synthetic storm shell. Yep, Exactly! We have long recommended a pure storm shell such as Helly Hansen Impertech (please check with Alex if you need a shell). Mostly the shell will remained stowed, but if you are living out of a small tent and facing sustained heavy rain or high wind, a shell is important to have. Extreme wind or sustained heavy rain is about the only time wool needs any help.
Cotton loves to absorb water … as much as 27 times its own weight in water … and water will suck heat from your body, even in moderate temperatures, because water conducts heat something like 25 times faster than does air. And the water absorbed by cotton is right at the surface of the cotton, where it touches your skin. Wool adsorbs water vapor internally ... water trapped inside a wool fiber cannot steal heat from your skin.
WOOL FEELS WARM TO THE TOUCH
When you touch wool on a cold day, it feels warm because it is a poor conductor of heat. That is, wool does not absorb heat from your body. There are two reasons for this. First, when you touch wool, you don't touch very much of it. The structure of wool is not flat … it is very curly and kinky and on a microscopic level, its surface is very rough. So when skin comes in contact with woolen fabric, it simply does not touch as much of the wool as other fabrics. Secondly, the cellular, chemical and biophysical structures of woolen fiber are all fine insulators.
In 1858 Coulier was the first to observe that when dry wool was moved to a moist room – when it adsorbed water -- it produced heat. This is known as the heat of sorption (usually considered to encompass both adsorption and absorption). Experiments have shown that human subjects can perceive the heat of sorption of water vapor by wool garments in typical winter conditions, particularly if the woolens are thoroughly dried before use. Some claim a kilogram of merino wool can release as much heat over 8 hours as an electric blanket. This is just one of the reasons wool keeps you warm even when it is wet.
I've been studying up some on this idea of wool generating heat ... and I definitely cannot say that I understand it! But, here is the nub of what I've gleaned. Within the wool fiber are protein structures that like water. When water infiltrates wool fiber from the end or by slipping between the scales that coat the outside of the fiber, the water is bound to sites on the internal proteins. When water binds to these sites, heat is produced. According to Wool: Science and Technology, edited by Simpson and Crawshaw, “When 1 kilogram of wool is taken from 40 to 70% RH [Relative Humidity], 160 kJ [kiloJoules] of heat are evolved. The main effect of this is to slow down the impact of moving between hot dry atmospheres indoors and cold damp atmospheres outdoors.” I quoted it because I don't really understand it! Eventually I will do some more research but for now, that's all.
Another reason wool can keep you warm, even when wet, is that woolen garments can hold and hide up to 60% of their weight in water before they even begin to feel wet. Each individual wool fiber can absorb – internally -- 35% of its weight in water. This 35% weight gain is trapped within the complex internal structure of each fiber where it cannot touch the wearer. But also, because of the physical shape of woolen fiber, the rough surface of the fibers and their crimp (kinkiness), additional water – 25% of the weight of the garment -- can be contained between the fibers that comprise the yarns from which our garments are woven. Fine wool fibers, that is, small-diameter wool fiber, not only feels softer against the skin but is also capable of absorbing/adsorbing a higher percentage of its own weight in water before feeling wet … both within each fiber and between the fibers.
Wicking is a popular talking point these days … how well a fabric can transport moisture away from the skin. But it is critical to keep in mind the entire story about wicking. On a cold day, when a fabric picks up moisture from the skin and transports it away from the body, the moisture is quite likely to condense when it goes up against the cool temperatures that prevail away from the surface of the skin. When this happens, the synthetic fabrics re-absorb the liquid, and the body must expend additional energy to re-heat the liquid to cause it to again be transported away from the skin. This cycle can continue causing the body to lose precious energy. Because wool adsorbs and transports moisture more slowly than synthetics, the repeated vaporization cycle is avoided. Wicking is great in summer when heat needs to be dissipated, but wicking needs to be tightly controlled in winter when heat needs to be retained. In the cold, it is best to avoid sweating, regardless of what you are wearing. But in cold or in heat, it is interesting also to think of the way wool adsorbs and releases moisture.
DO YOU SUPERWASH YOUR WOOL?
No. Superwashing is a treatment that enables woolen garments to be washed (agitated) and dried mechanically without worry about shrinking. However, superwashing changes the physical and chemical surface properties of woolen fibers in ways that significantly degrade performance. Mechanical washing and drying is a nice convenience but not nearly enough of a convenience to sacrifice performance. WeatherWool is all about letting wool be wool.