Dec 11 2012

Wild about Wool



Oh Wool! Would that I could express the many ways I love thee. In gloves, underwear, vests, shells, jackets, socks and pants. For your silky softness. The magical way you combat odor. Your longevity, naturalness, even your hand is a pleasure to hold and the warmth you control, warm when it’s cold and cool when it’s not round out your paradoxical qualities. Even your musty smell when wet can be appreciated when you consider that wool creates heat when it is wet. It has a hydrophobic shell around the fiber, so it wicks moisture wickedly fast, but has a core that absorbs water vapor, creating heat and re-radiating it back like a thermal regulator.

Supernatural Wool

Amazing view of the structure of wool, courtesy The Heirarchy of Wool

Man does not yet know how to create such amazing paradoxical qualities in a fiber, and even if he could, it’s natural to prefer natural over man-made. A closer look at the construction of wool at the microscopic level makes the design of insulating fabrics like polarguard look crude and simplistic. Mechanically wool is a combination of interleaved fibers, or chains of molecules we emulate in the way fibers are spun, but wool has these same properties intrinsic inside itself.

To keep it simple, wool has a scaly exterior layer called the cuticle. This layer is hydrophobic, and acts to wick moisture. The scaliness of the cuticle is what contributes to its prickly sensation for larger diameter fibers, but ceases to be noticeable with smaller ones. It is also what can cause a garment to shrink after drying, since the scales cling to each other and compress the garment.

Manmade fibers inevitably try to copy Nature’s qualities. Except they aren’t as eco-friendly, or renewable.

Inside this outer sheath is a core that is hydrophilic, meaning it absorbs water vapor, up to 30% of its weight in water, which allows it to regulate heat better. The absorption of water vapor into the core prevents the growth of microbes on the outside since the moisture is then internal. In combination with a substance known as lanolin, which is inherently antibacterial, you have a one-two knock out punch that is at the root of combating odor.

What most people notice though is the basic insulating properties of wool which come from a naturally crimped (bent and crinkled) construction which creates millions of tiny air spaces within the fibers that prevent conduction. The crimps add to the soft nature of the fiber, as well as adding to the ability for wool to retain its shape.

Quality VS Quantity
The only issue one could have with wool that makes any of sense is the high price. But that is only the immediate cost. In general, and there are brands and batches that are of lesser quality, but usually even the least durable brand of wool is better than your average rotten cotton version. Marino wool exceeds the useful life of other fabrics making them less expensive in the long run, at least, if you get a good brand.

How can you tell what are the better brands, or products? Since wool is, by itself a rather phenomenal fiber, and universally available, the differences show up in how the wool is processed.

Wool is separated by where it grows on the sheep. The softer fibers typically come from the chest.

Step one is separating the size of the fibers. Here is where wool gets its reputation as a warm but scratchy fiber. Cheap wool gloves and socks are make from rag wool, about 35 microns in diameter. You want fibers half that diameter, give or take a few microns. Consider cashmere, one of the finest, silkiest fabrics known to man. It is a high grade wool with a diameter in the range of only 15 microns. To simply feel comfortable, fibers with diameters in the 20 micron range are plenty good enough. In fact, this is the key ingredient you should look for in a company’s description of their product. If it’s at least 24 microns, with smaller being better, it will feel smooth and soft.

There are other things that manufacturers can do to improve the softness of wool, or the versatility of their product. Most manufacturers of performance socks are weaving extra padding in specific zones or elastic for hugging your foot. Some models blend in other fibers, for enhancing wicking and/or durability. With blends you simply need to consider the ratio of the blend to see how much the performance of the wool is enhanced or reduced.

Caring for Wool
In general, you should wash cold and air dry to maximize the life of a wool garment. Unless it is a worsted wool (pre-shrunk) it will shrink if you tumble-dry with heat.

Herewith a short list of recommended products:

Using Alpaca wool, Dahlgren makes an awesome compression ski sock that is thin and smooth, but still warm and comfortable. Part of the warmth factor comes from the use of spandex to create a sock that aids circulation for more energy. Excellent for backcountry skiing.

Heli Ski de Cuir.
Wool inside,
leather out.

Dale of Norway
Hands down, Dale of Norway makes one of the best base layers I use regularly. Simple, smooth, durable. Or decadently soft and durable.

Don’t ask me to pronounce these, but Hestra combines two of the finest natural ingredients to produce the Heli Ski de Cuir glove. Wool liners with a leather outer shell. Can leather get wet? Yup, so can wool. Wool dries well, and leather can be treated to make it water resistant. You just have to apply bees wax or some other waxy stuff to make it repel water. On a cold day everyone likes how leather absorbs snot.

Those who see me on the street are likely to see me wearing an Ibex full zip, thick wool jacket with a Backcountry logo on it (ala the Shak). Super warm, super breathable, not waterproof one iota, but it is an excellent insulating layer under a shell when the temperature hovers around zero. Ibex now offers the same jacket with the waterproof shell included. Since it is wool it has an amazing range of temperatures where it is comfortable in, not just the cold zone, but also when it gets warm without being oppressively hot. For those who like to think globally, yet act locally, Ibex sources its wool from Montana, and does all the processing stateside.

Still have a 200 weight Icebreaker top that is over 10 years old. Although it has washed down to a 150 weight, it still keeps me warm, transfers sweat well, and combats odor in spite of the sweat. It has wicked wetness in some pretty awesome mountains.

Point 6 Active Crew sock 67% merino, 29% nylon, 4% spandex

Point 6
Peter Duke is the wool guru who took wool to a new level with Smartwool, then left to do it better still with Point 6. Peter is adamant about quality and when you buy a pair of Point 6 socks you know they’re going to last. Midweight socks are excellent for super cold days, and super durable. Nothing better for winter warmth.

More on Wool:
Textile School

Types of wool.

The Hierarchy of Wool by Ji-Huan He

Wool’s Virtues

© 2012

  • http://ern.reeders.net.au/blog/ Ern Reeders

    Agree that wool is good stuff for garments, partic. the superfine for base layers.  No rank smell of sweat over 4-5 days of touring is uncanny.  My impression though is that when looking for higher insulation values the warmth to weight ratio isn’t as a good as fleece.

  • Dostie

    You’re on to something there, but it doesn’t quite tell the whole story. In my experience the same thickness of fleece VS wool, the fleece does feel warmer. But, I don’t actually feel colder with the wool, the fleece just feels warmer. However, Wool has a much greater useful temperature range. Thus, for the same thickness of fleece I will overheat in warmer temps while I remain comfortable with wool. And, or course, the ultimate insulation is another natural product – down. YMMV.

  • http://ern.reeders.net.au/blog/ Ern Reeders

    Like ‘wool’, ‘fleece’ covers a multitude of sins, no, er,  products.

    IME quality fleece is comfy over a wider range of temps than cheap stuff.  I’m impressed by Thermolite for its balance of insulation range, bulk and weight.

    Coming from an Aussie this may sound like treason but what the hell.

    Yeah, nothing can match a down garment for the weight/insulation/packed bulk ratio. But I believe animals may get injured in its production.  Again, what the hell ;-)  I eat them too. In moderation of course.