When choosing your outdoor clothing, the type of fiber you choose makes a big difference in that apparel’s performance. This makes it important to know as much as possible about fiber types and characteristics.
Wool is a natural fiber that has seen a great deal of use in outdoor outerwear. Certain types of wool are also seeing increased use in high-performance sportswear, including socks and shirts. But not all wool performs the same way! There are many differences between the types of wool, including key performance and comfort characteristics.
What Is Wool?
Wool fabric is cloth that has been made from the spun hair of various animals. It is a natural fiber and has an ancient history, having been used for thousands of years starting in the Middle East and northern Africa. Even in the hottest places, wool was used– the Bedouin nomads of the Arabian peninsula, for example, continue to use wool for their tents and outerwear because of how good it is at insulating. The thick outer layer of wool gets hot, but it doesn’t transfer that heat to the inner layers of fabric.
Wool’s incredible performance comes from the physical structure of the fibers. Wool has a thin inner core of the hair, surrounded by an outer layer of tiny overlapping keratin scales. Each wool fiber is like a tube, and that allows the wool to maintain its elasticity and the wavy texture called crimp. Each strand of wool can bend over 200,000 times, which makes it very durable, and the combination of inner elasticity and outer toughness makes it highly resistant to breakage.
Wool is also a great insulator, and unlike every other type of fiber, wool maintains its insulating abilities when wet. Wool is naturally water-resistant due to the keratin scales and natural oils present in animal hair. The ability to insulate while wet has made wool a must-have fiber for many outdoor pursuits because it can keep you safe from hypothermia.
Wool is also great at moisture-wicking. It can absorb about ⅓ of its weight in moisture, and the structure of the fibers keeps this water on the outside layer of fabric. The twisted, interlocking fibers channel the water away from your skin and deposit it on the outside of the clothing layer. This has led to an increase in popularity for merino wool as a base layer because it’s comfortable to wear next to the body and is highly effective at wicking away moisture.
Another trait of wool that many outdoor enthusiasts appreciate is that it’s naturally antimicrobial and resists odors. Wool does require a little extra care in the laundry, but you don’t have to wash it as frequently because it doesn’t get gross. Wool fibers also keep dirt on the surface of the material, making it stain-resistant. Today, many types of wool threads and garments are treated with superwash technology, which makes it possible to put wool clothes in the washer and dryer without worrying about damaging the fabric. But even non-superwash wool can still be cleaned with a little TLC!
Finally, wool is extremely fire resistant. Wool has a very high burning temperature– 1,058 degrees Fahrenheit. To put that in perspective, most campfires burn at about 600-900 degrees Fahrenheit. If wool does catch on fire, it does not stick, drip, or melt, and will self-extinguish when removed from heat. Wool also has a naturally high nitrogen and water content and needs more oxygen and flammable materials than other types of fiber to keep a fire going. Finally, wool’s cross-linked dual-core structure swells when heated, which creates an insulating layer to keep the flame from spreading. This is why firefighting gear is frequently made from wool.
Does All Wool Come From Sheep?
While most people associate wool with sheep, the term refers to the fiber produced by a number of animals. Wool is the soft undercoat of hair of certain mammals and consists of thin, wavy or curly hairs that never stop growing. With animals that have been domesticated for their wool, like sheep, this undercoat might be the only coat of hair they have. For other species, the wool might need to be brushed out from the main coat.
What About Fleece?
Fleece might sound like a type of wool, but it’s not actually wool. The name was intentionally chosen to sound like a type of wool because fleece was invented to mimic some of wool’s properties. Fleece is actually a synthetic fabric that performs very differently than wool does. We have an article comparing wool and fleece here that you can read if you’d like more information.
The Types Of Wool
The garment industry recognizes ten primary types of wool: Lambswool, Merino, Shetland, cashmere, angora, camel hair, alpaca, vicuña, and qiviut. There are other types of wool that are used for textiles we don’t wear, like rugs, and there are some minor types of wool that we’ll touch on here as well. All the types of wool are well identified on the garments that are made from them, as the wool industry is very diligent about labeling and identifying the source of the fibers it uses.
Lambswool comes from the first shearing of a young sheep, usually when the animal is around seven months old. This wool is very fine and has hypoallergenic properties. The fibers themselves are less than two inches long and are quite thin, making them elastic and almost slippery on the skin.
- Fiber Origin: Young sheep of any breed
- Width: No more than 25 microns
- Typical Use: Sweaters, blankets, socks, suits, sport coats, and other clothing
- Notable Feature: The softest type of wool
Merino wool comes exclusively from the Merino sheep. This breed was established in Spain, but now more than 80% of all Merino sheep live in Australia. This breed of sheep was developed in hot weather, and so the fibers are naturally very fine and light compared to other types of wool. Merino sheep also produce more lanolin than other types of sheep, which means that their wool has to go through an elaborate scouring process to remove most of the oil. This is part of what makes Merino wool more expensive than other types of wool. However, the durability of Merino garments and their high performance make the high price tag worth it for many people.
- Fiber Origin: Merino sheep
- Width: 17-24 microns
- Typical Use: Base layers, outerwear, socks, high-performance sportswear, summer clothing
- Notable Feature: The best wool for base layers
Shetland wool is a thick, lustrous wool that’s very popular for sweaters and outerwear. It’s an unusual type of wool in that the fleece is not uniform on the sheep– an individual sheep can give very fine wool from the animal’s neck and very coarse wool from the flanks. This is because Shetland sheep are a primitive, double-coated breed. Their long, coarse guard hairs are great for rugs and textiles that need to be more durable than comfortable, while the smooth, thin inner hairs are great for producing shawls, socks, and other comfortable garments.
Shetland-style wool can come from other sheep breeds, like the Navajo Churro, Scottish Blackface, Icelandic, and Karakul sheep; however, these sheep are relatively rare and don’t have much of an industry presence. This is the case with many sheep breeds; there are lively cottage industries that produce wonderful wool garments from these more unusual breeds, but to keep things easier to understand, we’re focusing on industrial wool use and categorization.
- Fiber Origin: Shetland sheep
- Width: 30-40 microns
- Typical Use: Sweaters, outerwear, socks, rugs, blankets, shawls
- Notable Feature: Highly water-resistant; Shetland wool sweaters are prized by fishermen
Mohair is goat wool that comes from the Angora goat. Angoras are a double-coated breed and the guard hairs from the top coat are often included with the undercoat when the animals are sheared. This gives the fiber a particular fuzziness that’s soft and warm. Angoras are from mild climates and produce a thick, long fiber that’s smoother than many other wool types.
- Fiber Origin: Angora goats
- Width: 25-45 microns
- Typical Use: Sweaters, socks, scarves, shawls
- Notable Feature: Fuzzy and soft, and takes dye more easily than other wools
Cashmere is another goat fiber, but unlike mohair, cashmere only uses hair from the undercoat of several different goat breeds. Many breeds produce this fiber, but because it’s only the undercoat, it takes hair from at least two goats to make one sweater. The wool is about the same thickness as ultrafine Merino, but much more expensive. However, it is much softer than even Merino wool.
- Fiber Origin: Goat
- Width: 14-30 microns
- Typical Use: Hats, gloves, scarves, shawls
- Notable Feature: The finest type of wool
Despite the name, angora fiber does not come from Angora goats. Instead, it comes from rabbits. There are several types of angora rabbits, but the four most common are English Angora, French Angora, Giant Angora, and Satin Angora rabbits. Angora fibers are hollow and smooth, so they are extremely warm and soft.
Angora is more delicate than most types of wool, so it’s usually mixed with other fibers to increase its durability. Angora production is labor-intensive because the extreme fineness of the fiber makes it prone to matting and felting. This means that angora breeders have to brush and comb their rabbits to collect the fiber every day. Since this takes a lot of time and Angora rabbits have a low yield compared to other wool-bearing animals, angora is an expensive fiber.
- Fiber Origin: Rabbits
- Width: 12-16 microns
- Typical Use: Hats, scarves, combination with other fibers to reduce weight and add softness
- Notable Feature: The lightest type of wool
Camel hair is a durable fiber that makes excellent coats and outerwear. Although looking at a camel might lead you to assume that the fiber is rough, camel hair is hollow and finer, and longer than sheep’s wool. This results in a fiber that’s lighter than sheep’s wool and about as soft as cashmere. Camel hair comes from Bactrian camels (the two-humped kind), which live in cold regions like Mongolia, northern China, and Russia. When these animals molt in the spring, the downy undercoat is collected to be turned into cloth.
- Fiber Origin: Domesticated camels
- Width: 20-23 microns
- Typical Use: Coats, dressing gowns, scarves, outerwear, blazers, sport coats, suits
- Notable Feature: Highly versatile; when combined with the camel’s guard hairs, the fiber becomes stiff and strong enough for tents and rug backings
Alpaca fiber is completely hollow, making it incredibly good at insulating. It comes from the alpaca, a small camelid from the Andes Mountains in South America. The places where alpacas are naturally found are extremely cold and dry, so their fiber has to work hard to keep them protected.
- Fiber Origin: Domesticated alpacas
- Width: 19-35 microns
- Typical Use: Socks, gloves, scarves, sweaters
- Notable Feature: Hypoallergenic– no lanolin
Vicuña are the wild relatives of alpacas that are sheared for their fiber every spring. There are only a few thousand of these animals, and the Peruvian government protects them and limits how often they can be caught and harvested for their fiber. Shearing the vicuña has been an Andean tradition since the days of the Inca empire when the fiber was reserved for use by royalty. Today, you might as well be royalty if you want something made from genuine, unmixed vicuña fiber; a vicuña scarf can cost over 3,000 dollars.
- Fiber Origin: wild vicuña herds
- Width: 8-12 microns
- Typical Use: Scarves, wraps, cardigans
- Notable Feature: Most expensive type of wool
Qiviut is wool that comes from the undercoat of the Arctic muskox, which is bred in Canada and Alaska. Interestingly, the muskox isn’t actually an ox– it’s more closely related to goats! This fiber is somewhat difficult to obtain because you can’t shear muskox to collect it. Instead, the wool is collected when the undercoat is shed in spring by either combing the animals or picking the shed wool up off the ground. Qiviut is very fine, soft, and strong. Its main point of interest as a fiber, though, is how warm it is. Qiviut is about eight times warmer than any other type of wool and does not shrink in water. This tough Arctic fiber is very popular for blankets, coats, and other cold-weather gear.
- Fiber Origin: Musk Ox
- Width: 11-17 microns
- Typical Use: Blankets, coats
- Notable Feature: Eight times warmer than other wool types
Other Types of Wool
In addition to the main types of wool, there are a few other types that are worth mentioning.
- Cashgora: the result of a crossbreed with an Angora goat mother and cashmere goat father, this fiber is finer than mohair but not as fine as cashmere
- Chiengora: not produced on an industrial scale, but something you may see from time to time if you’re looking at handmade goods, chiengora is yarn spun from dog hair
- Cria: the alpaca equivalent of lambswool
- Llama: related to the alpaca, llama wool is used less frequently because it isn’t as soft and the fibers are weaker and coarser
- Suri: a type of alpaca with a smoother hair surface; less than 10% of alpacas are Suri alpacas
The Final Word On Wool
As far as high-performance fibers go, wool is a superstar for many reasons. But that doesn’t mean that wool is right for every application! Wool is a great fiber, but sometimes you need a different type of performance than the performance it offers. There are many factors that need to be weighed against each other when you’re choosing your outdoor apparel.
When you’re shopping for gear and outdoor clothing, we want you to make the best decision possible. Only you know the conditions in which you like to hike, fish, or spend time outside, and only you know what makes you comfortable. It’s our hope that you use this guide and our other guides to fiber and fabric types to make the best choices that keep you safe, comfortable, and happy.
If you’d like to know more about fiber, why not consult our other guides, too? We have guides to the following fabric types:
If you want to know more about these or any other fibers, let us know!
Max DesMarais is the founder of Hiking & Fishing. He has a passion for the outdoors and making outdoor education and adventure more accessible. Max is a published author for various outdoor and marketing websites. He is an experienced hiker, backpacker, fly fisherman, trail runner, and spends his free time in the outdoors. These adventures allow him to test gear, learn new skills, and experience new places so that he can educate others. You can read more about him here: hikingandfishing/about