Wool is a protein fiber, made up of overlapping scales that protect the inside from the fiber, thereby repelling most foreign substances. A wool fiber is made in a zig-zag, crinkle shape that helps it spring back into shape, unlike any other fiber. Even carpet mills try to duplicate wool, because it’s so resilient. Because it comes from really short staple fibers, it has to become spun to make a yarn that’s then used for rugs. Wool is damaged by temperatures above 150 degrees, and so its must be cleaned at lower temperatures to prevent felting. Felting is the procedure of causing a texture change that is permanent, by using heat and agitation that makes the fibers lay flat. In no way do you want to permit your sacramento carpet cleaning company to attempt to clean your wool rug with a truck mount machine.