Category: wool...

wool that has had no previous use is called virgin wool
wool fiber is mainly made of the protein keratin, which is more vulnerable to environmental and chemical damage than cellulose material in plant fibers
wool is wavy and may have up to 30 waves per inch
After all, the wool of a black sheep is just as warm. (E. Lehman)
Many go out for wool, and come home shorn themselves. (M de Cervantes Saavedra)
Selective sheep breeding eliminated most of the long, coarse hairs forming a protective outer coat, leaving the insulating fleecy undercoat of soft, fine fiber.
The amount of crimp corresponds to the thickness of the wool fibers. A fine wool like Merino may have up to a hundred crimps per inch, while the coarser wools like karakul may have as few as one to two crimps per inch.
Many people consider themselves to be allergic to wool because they have an adverse reaction every time it touches their skin. However, a true allergy to wool is actually rare. Most people who have a reaction to wool do so because they have sensitive skin, and they would likely have a similar reaction to any coarse fiber.