Wool
Wool is a natural animal fiber, usually shorn from sheep, whose crimped, scaly structure traps air and makes it useful for warm textiles.
Keratin: A family of structural proteins that forms hair, wool, feathers, and other protective tissues. Wool fibers consist primarily of keratin, whose structure gives them strength and flexibility.
Sheep: Domesticated ruminant mammals raised worldwide for meat, milk, skins, and fleece. Sheep provide most of the wool used in global textile production.
Merino wool: Fine wool from Merino sheep, valued for its soft handle and use in apparel. Its fine fibers make Merino wool suitable for garments worn next to the skin.
Cotton: A soft plant fiber obtained from the seed hairs of cotton plants and spun into textile yarn. Cotton is a common natural-fiber alternative with different moisture and insulation behavior.
Mulesing: A sheep-management procedure that removes skin around the breech to reduce flystrike risk. The practice is a contested welfare issue in some Merino wool supply chains.
Wool crimp: The natural waviness of wool fibers, shaped by their growth and internal structure. Crimp traps insulating air and helps wool yarns hold together.
Fleece: The coat of wool covering a sheep or another wool-bearing animal. A fleece is the raw coat removed during shearing before textile processing.
Cashmere: A fine, soft animal fiber obtained from the undercoat of cashmere goats. Cashmere is often compared with fine wool but comes from goats, not sheep.
Silk: A continuous protein filament produced by certain insect larvae, especially silkworms. Silk is another animal-derived textile fiber, but it is a smooth filament rather than fleece.
Flystrike: A condition in which blowflies lay eggs on an animal and their larvae damage its tissue. Flystrike is a major sheep-welfare concern cited in debates over mulesing.