Rug yarn is made from the "less desirable" fiber that comes from our alpacas. Sometimes that is all the fiber the animal produces and sometimes it's just the belly and leg fiber. So we never know how much we will have.
Rug yarn is core spun on a cotton core and it's thick and fluffy and also a bit hairy. Our hand woven rugs are made from this yarn. It will felt slightly, reducing it's "hairyness", if it gets wet and goes through some agitation or shock treatment such as going from HOT to COLD water. Because it's already spun onto the core, this is an OK thing to do. But you would not want to do that with raw fiber.