Wool and wool fibers The most plausible reason that we itch from wool is because of "the mechanical rubbing of the fabric on the skin. And there are two factors determining the “itchy” feeling: the fiber diameter measured in microns, and the fiber structure (the amount of crimp) of the wool." "The wool fiber grows out of follicles on the sheep skin and is covered with a natural grease. In comparison to a general sheep’s wool, our hair has a double fiber diameter, and four times that of merino wool (a sheep breed). The sheep’s wool fiber grows in crimps, which is the wavy pattern of the wool, which corresponds to the fineness of the fiber." The more crimp, the smoother the wool. Merino wool can have as many as 100 crimps per inch. Scale is the roughness of the surface of the fiber. Wool in general is categorized into three major groups defining fine wool, from medium and course wool. Fine wool <= 24.5 microns Medium wool 24.6-32.5 microns Coarse wool >32.5 microns So how large of a diameter of the fiber can we feel safe that the wool will not itch? According to the article by Michaela Zallmann et al., 2017, with the title : Debunking the Myth of Wool Allergy: Reviewing the Evidence for Immune and Non-immune Cutaneous Reactions, they found that the fibers of superfine and ultra fine wool garments, with mean fiber diameters of 15–18.5 µm and 11.5–15 µm respectively, would not generate the mechanical force required to induce mechanical itching and irritation. In general, below 19 microns the wool will not feel prickly. Thus, we can assume that most people will not feel the itch by choosing wool of the fine wool category. Which wool would we find within this category? First and foremost, we are talking about the merino wool. Merino is as mentioned a specific breed of sheep that has fine wool fibers. It’s among the softest wool on the market, though not all merino wool is created equal. Each wool category is divided into individual standards. Standard merino wool is about 23 microns; fine merino around 18 microns; superfine is 16 microns, and ultra-fine is less than 15.5 microns. The long length of the Merino fiber also makes it resist pilling better than shorter fiber wool. And, most of these happy sheep are brought up in Australia and New Zealand. The merino wool is most often used alone or combined with a small percent of Tencel, or synthetic fabric to produce wool base layers, the layers we use directly on the skin. Tencel is a man-made cellulosic fibre, extracted from wood pulp to form fiber strands in a solvent spinning process. Alpaca, baby alpaca, cashmere, and mohair, and a mix of those, along with the merino wool are commonly used to produce knitwear like sweaters, cardigans, jackets, hats, socks, mittens, scarves, throw blankets, shawls etc. Alpaca wool Alpaca wool is a type of wool that is derived from the fibers that naturally grow on alpacas. These animals are known as camelids since they are similar to camels, and alpacas are native to South America. There are two breeds of this four-legged animal: the Huacaya alpaca and the Suri alpaca. Alpaca wool is also classified according to its diameter: Alpaca, Baby Alpaca and Royal Alpaca. The diameter of the Alpaca wool fiber is 23.1 - 26.5 microns, that of the "Baby Alpaca" is about 14 - 23 microns, while that of the "Royal Alpaca" is the result of the selection of the best and finest Alpaca Baby fibers whose diameter can go up to 12 microns. Wool produced by alpacas can be made into a very fine yarn, which means that it can be used in a variety of applications that aren't feasible when using sheep wool. Alpaca is often blended with merino wool, and other wool types because of the fine fibers. Cashmere Cashmere is a type of wool that is made from cashmere goats and pashmina goats. The name is derived from Kashmir, a region in Northern India that still produces cashmere. Mongolia and Iran are also producers of this beautiful wool. Cashmere is very soft and insulating, and the fibers are fine and smooth. Cashmere is often blended with other types of wool, like merino, to give it added weight, since cashmere fibers are very fine and thin. But a garment can only be labelled as cashmere if: the fiber consists of the fine (dehaired) undercoat fibers produced by a Cashmere goat (capra hircus laniger). the average diameter of the cashmere fiber does not exceed 19 microns; the cashmere fibers in the wool product contain no more than 3% (by weight) of cashmere fibers with average diameters that exceed 30 microns. Cashmere is one of the most expensive forms of wool because the production and manufacturing process is complicated. First, the goats naturally shed their coats in the spring during molting season, and the wool needs to be gathered. Wool can either be gathered by combing the goats’ coats with a comb, which usually yields less coarse hair; or wool can be shorn, but that results in much more of the rough overcoat and requires more de-hairing later. Most cashmere is made by combing, as it yields a high-quality cashmere. Cashmere wool that has been shorn is often lower-quality cashmere because it is more prone to pilling, as the fibers are much shorter than if they were combed. After the wool is gathered, the coarse overcoat hairs must be separated from the fine and soft undercoat hairs, which eventually become the cashmere. Once the fibers are separated, they are assembled into bales spun into yarn, which is dyed and knit or woven into fabric. Mohair Mohair is a soft wool that comes from the hair of the Angora goat. The diameter of the fiber increases with the age of the goat, and the thinner fibers from young goats are used more for clothing, like sweaters, while the thicker, coarser fibers are used for carpets, upholstery, drapery fabric, and outerwear. Mohair is more expensive than standard sheep’s wool because the production process is more involved, and as a result, it is considered a luxury fiber, like cashmere or Angora. Considered one of the oldest fiber textiles in existence, mohair originated in the mountains of Tibet, where the Angora goat originally lived. The Angora goat was introduced to Turkey in the sixteenth century, in the Turkish province of Ankara where the name “angora” comes from. Angora goats were farmed almost exclusively in Ankara until 1849, when the goat was given as a gift to a United States cotton farmer for his service helping Turkey cultivate cotton. Today, the mohair industry is centered around South Africa, which is the largest farmer of angora goats and exporter of mohair, along with Argentina, Turkey, and the U.S. state of Texas. To a lesser extent, Australia and New Zealand also produce and export mohair. Animals sorted by fiber-diameter. This Website: has a fun grid of animals that are sorted from the ones with wool with the smallest fiber diameters on the upper grid to the animals with wool with larger fiber diameters at the bottom of the grid. Ordinary wool sheep is not even included there. Other animals, as the alpacas and llama breeds, in addition to cashmere goat breeds, and yaks, even bison, also have a smaller fiber diameter than those of ordinary wool sheep. Conclusion to the itchiness question: In conclusion, to avoid itchiness use clothes made from wool with small fiber diameters like merino, baby alpaca, and alpaca, as a base layer – the layer closest to the body. If you are very sensitive to wool, use these kinds of wool also for your outer layers. When buying wool clothes, it is a good idea to check the information about how the wool is selected and produced by the wool manufacturer. Manufacturers who keep a high-quality standard on their wool and wool production will always give you this information on their web site. With thanks to these sources: https://www.gentlemansgazette.com/wool-explained/ https://www.knittingthenaturalway.com/fiber-diameters https://www.alpacainfo.com/academy/article/4662/u.s.-alpaca-fiber-standard https://merinowoolgear.com/is-merino-wool-itchy/ https://www.learnaboutwool.com/globalassets/law/resources/factsheets/secondary/gd3270-secondary-fact-sheet_2019_a.pdf https://goodonyou.eco/how-ethical-is-tencel/
