Alpaca fiber has good thermal properties. This is the result of two characteristics. First, alpaca fiber is hollow, which helps with insulation. Second, the fiber crimp gives a bulkiness in the yarn. This bulkiness prevents the fibers from packing too closely together.
Consequently air is trapped in the garment, providing further insulation.
Fiber Fineness Fiber judges evaluate fiber mainly by putting their hands on the alpaca's fleece. Alpaca fiber can be scientifically measured by cutting a 2 inch fiber sample from the side of the alpaca and sending it off to a testing laboratory. The results will be reported in a histogram which graphically shows fiber data for your sample. As an animal matures, its fiber tends to have a higher or coarser micron value. Males sometimes possess a higher micron value than females.