Smartwool Merino Wool Fiber - The Smart Choice

What makes Smartwool socks and clothes the best year-round choice

Smartwool Fiber
You won't find better gear to keep you comfortable in all conditions than Smartwool, whether you're out tromping in rain, heat or hail. It's the best fiber in the world for cold and warm, wet and dry weather use, combining comfort and performance into one versatile package.

Smartwool Merino woolAbove all else comes the extraordinary comfort. Far from the itchy wool of yesteryear, Smartwool's fibers are luxuriously soft. They come from New Zealand's specially bred Merino sheep, whose super-fine fibers are as fit for pajamas as they are active-wear. Combine this with a production process that removes all itch and shrink and you get a layer you'll never want to take off - even after the day's journey brings home.

But extraordinary comfort is only the beginning. The real tale lies in the fiber's performance. Over the eons Smartwool's fibers have evolved to keep Merino sheep warm in the alpine winters and cool in the southern summers. That same natural temperature regulating process works for people as well. The secret is that each fiber harbors thousands of tiny air pockets which, like insulation in your house, act as a buffer against heat and cold. The fibers naturally regulate temperature, whether you're climbing an 8,000-meter peak or running an Arizona marathon. They keep you warm when it's cool and cool when it's hot.

The fibers also move moisture faster than any other material on the planet. This means you stay drier longer and can say goodbye forever to the clamminess that comes from other materials. Unlike synthetics, which have to wait for moisture to condense before wicking it away from your skin, Smartwool's fibers are porous, allowing them to absorb vapor and transfer it before it condenses. This saves a step by letting them wick and evaporate moisture at the same time, transporting it in both liquid and vapor stages. When it's hot, this creates a mini air-conditioning unit and vapor stages. When it's cold, this keeps bone-chilling moisture at bay.

And our fibers even have one more trump card. As well as being the most efficient and versatile fibers on the planet, their dryness also makes them the most odor-free, free of the stink that plagues synthetics.

Fiber Up Close
Smartwool FiberThere is no other fiber quite like Smartwool. It is truly unique. This is due to its own inherent properties and the application of "Smart Technology" by Smartwool comfort engineers. Before we talk about how and why Smartwool is so comfortable, let's take a closer look at the make-up of a Smartwool fiber.

Resilience
Smartwool fiber is made up of 90% keratin, a very resilient protein which is resistant to chemical and bacterial attack, naturally flame retardant and able to withstand the rigors of everyday wear and tear.

Diameter
Smartwool fibers have a very fine micron, being between 1/10 and 1/3 the thickness of a human hair, making Smartwool exceptionally soft and comfortable.

Protection
Each Smartwool fiber has a waxy coating of cuticle cells, which helps repel water as a liquid but lets water move through in a vapor state and ultimately be evaporated out into the atmosphere.

Crimp
The two cells found in the outer layer of Merino fiber are believed to cause the crimp or wave. It is this crimp that creates the natural stretch in Smartwool fabrics and forms thousands of tiny pockets of air to promote a personal microclimate between fabric and skin.

Efficient
Smartwool FiberYou stay drier for longer because Smartwool wicks, absorbs and evaporates more efficiently than any other fiber, including synthetics. This is due to the exceptional moisture management properties of Smartwool. Smartwool's ingenious moisture management system ensures all day comfort.

Sweat is removed from the skin's surface as vapor, through evaporation. The vapor then condenses and can compromise your personal microclimate (the air trapped between fabric and skin) causing a clammy sensation. Sweat needs to be removed from the skin's surface or from the microclimate to ensure that comfortable cool and dry conditions are maintained for the garment wearer. Smartwool manages moisture different than other fibers, it absorbs the moisture vapor before it has a chance to condense into a liquid.

Smartwool's moisture management system works between the fabric and your skin, and between the fabric layers. Water vapor moves naturally from a high to low humidity environment, even through the Smartwool fabric. If you are wearing Smartwool layers and a waterproof/breathable outer layer (such as a jacket) then the water vapor can be transported and released keeping your personal microclimate comfortably cool and dry. The moisture management system works equally as well with our Smartwool socks.

Not only is it rain resistant, Smartwool fiber is able to absorb water vapor and then release it into the atmosphere. It achieves this by absorbing moisture vapor from the high humidity environment next to your skin and releasing it into typically less humid environment outside the garment. This process of absorbing and releasing moisture occurs through "hydrogen bonding" where the negatively charged oxygen atom in the water vapor molecule is attracted to the positively charged hydrogen atom in wool's protein (keratin) backbone. This attraction is similar to that of two magnets with oppositely charged poles. Negatively charged oxygen atoms in the water vapor molecule are attracted to the positively charged hydrogen atom in wool's protein backbone.

Synthetic fiber is typically not effective at managing moisture as a vapor. It must wait for the vapor to condense into water droplets so it can employ a capillary action to wick moisture away from the skin. As a result, they absorb (chemically bind) little or no water and produce very little heat of sorption. Smartwool fiber moves moisture faster and more efficiently than synthetics as it doesn't require as many steps to maintain moisture control. Smartwool reduces the effect of this condensation on wearer comfort and can absorb moisture of up to 27% of its dry weight, therefore assisting in the process of thermoregulation.

The Result: More Comfort Over a Longer Period of Time

Versatile
Smartwool FiberSmartwool regulates your body temperature, keeping you cool in the summer and warm in the winter. No other fiber can match Smartwool's ability to retain necessary heat while removing any excess that may cause fatigue or discomfort. Tiny pockets of air, providing a buffering layer of natural air cooling or warming. Smartwool's natural climate control ensures comfortable performance in all conditions.

Smartwool fibers naturally create millions of tiny pockets of air, providing a buffering layer of natural climate control. This natural buffering capacity helps the body maintain a stable core temperature as it insulates the wearer against high ambient temperature in hot conditions and keeps the wearer warm by minimizing heat loss in cool and damp conditions.

In hot humid conditions, Smartwool fibers remain cooler than the body. As a Smartwool garment touches the skin, heat is transferred to the garment, acting as a coolant.

In cold climatic conditions, Smartwool fabrics actively generate heat through the 'heat of sorption' response i.e. Smartwool fibers are like small batteries, as they absorb moisture they release stored molecular energy in the form of body warming heat, perceptible in cooler ambient conditions. As the fiber dries and moisture is released, the energy is renewed and replaced.

Lactate build-up: When you exercise, your body's internal temperature rises as oxygen transfer decreases. This makes your muscles work harder, triggering lactic acid production. This results in fatigue, muscle pain, and even cramps. By allowing heat exchange, the body's internal temperature increases more slowly, impeding build-up of lactate in the muscle.

Temperature control: With regard to temperature control, let's compare Smartwool fiber with a synthetic like polypropylene: Smartwool fiber shows more favorable heat emission than polypropylene so you experience improved thermal regulation. Lower heat retention in Smartwool fiber means your core temperature stays lower so lactate build-up does not occur as readily. As a result the maximum stress threshold stays high when wearing Smartwool fiber so ultimately the wearer can work harder for longer.

The Result: More Comfort Across All Conditions

Odor Free
Smartwool FiberThe bacteria that cause odor can't build up on the Smartwool fiber. This means that even during intensive activity over extended periods of time you stay "fresher" longer.

Smartwool Fiber vs. Synthetic: The science is very simple, in fact this how odor comparison tests are conducted by many major research facilities. Wear a synthetic sock on one foot, a Smartwool sock on the other. Do this for 48 hours (go cycling, hiking, bouldering for a proper test). Let your nose be the judge. Be careful though, the smells from the synthetics can be quite alarming.

Smartwool versus Wool
Smartwool Fiber Selective Breed - Only the finest merino fiber is selected to become Smartwool. Smartwool buyers regularly visit growers in New Zealand and they pay close attention to the breeding lines. Smartwool sheep are raised under the most stringent of guidelines and all Smartwool fiber is selected to minimize or eliminate coarse fibers. The sheep are free range and live in a pristine, earth-friendly environment, which also contributes to the high quality of the Smartwool fiber.

Light and airy, feels good: It is a combination of the fine micron (fiber diameter), natural crimp and smart technology that gives Smartwool it's light and airy feel. In essence they have taken the itch out of wool. Through their process of stringent fiber quality specifications and smart technology, Smartwool ensures no itch causing (high micron) fibers make it into their products. Itchy wool typically occurs when the micron range is above 30 microns. All Smartwool fibers are far below this micron range, which is why Smartwool fiber is incredibly comfortable and soft to the touch.

In Summary, The Unique Comfort Properties of the Smartwool Fiber:
  • Smartwool fibers have the unique ability to absorb moisture as a vapor but repel it as a liquid
  • Smartwool fiber helps regulate your body's temperature, keeping you cool when it's hot and hot when it's cool.
  • Smartwool resists bacteria, which can cause odor.
  • The Smartwool fiber's fine micron and the application of "smart technology" makes it very soft and extraordinarily comfortable.
  • Smartwool fiber can withstand the rigors of everyday wear and tear.
  • Smartwool wearers stay more comfortable, allowing them to keep having fun.

Reproduced by permission from Smartwool.com