The fiber or fabric made from the fleece of sheep or lamb. However, the term “wool” can also apply to all animal hair fibers, including the hair of the Cashmere or Angora goat or the specialty hair fibers of the camel, alpaca, llama, or vicuña.
Wool vs. Hair or Fur: Most of the fiber from domestic sheep has two qualities that distinguish it from hair or fur: (1) it is scaled in such a way that it helps the animal move out burrs and seeds that might embed themselves into its skin; (Editor’s comment: I wish my dog’s hair did that!) and (2) it is crimped, in some fleeces more than 20 bends per inch. Both the scaling and the crimp make it possible to spin and felt the fleece. These characteristics help the individual fibers “grab” each other so that they stay together. They also make the product retain heat, as they trap heat in their bends. Insulation works both ways — bedouins use wool clothes to keep heat out.
The amount of crimp corresponds with the fineness of the wool fibers. A finer wool, such as merino, may have up to a hundred crimps per inch, where the coarser wools, like karakul, may have as few as one to two crimps per inch.
Hair, by contrast, has little if any scale and no crimp and little ability to bind into yarn. On sheep, the hair part of the fleece is called kemp. The relative amounts of kemp to wool vary from breed to breed, and make some fleeces more desirable for spinning, felting or carding into batts for quilts or other insulating products.
Wool grows in several natural colors such as black, brown (also called moorit) grey and the most commonly available white. Wool of any color takes dye easily and can be felted. Wool straight off a sheep is highly water-resistant. Wool also retains heat better than most fabrics when wet.
History: As a raw material, wool has been readily available since the widespread domestication of sheep and similar animals. The use of wool for clothing and other fabrics dates back to some of the earliest civilizations. In medieval times, the wool trade was serious business. English wool was a significant source of income to the crown. British laws controlled the wool trade, required the use of wool even in burials, and even forbade its American colonies to trade wool with anyone but England itself. Australia and New Zealand are currently the leading commercial producers of wool, however now Texas, New Mexico and Colorado also have large commercial sheep flocks.
Uses: In addition to clothing, wool has been used for carpeting, felt, and padding. Wool felt covers piano hammers, and it is used to absorb odors and noise in heavy machinery and stereo speakers. The ancient Greeks lined their helmets with felt, and Roman legionnaires used breastplates made of wool felt. Wool is also the main ingredient in creating flannel.