For 5,000 years South American people bred alpaca to be finer and
finer. The softness and warmth of alpaca comes from the fact that it is
the finest of all natural fiber at around 18-26 microns. Only cashmere
down around 14-16 microns thick is finer. In comparison, human hair is
about 100 microns thick. Spinners say that alpaca spins like butter.
Mountain climbers are wearing alpaca socks on their feet...testimony to
the fact that alpaca is four times warmer than sheep's wool.