And Duofold started the idea of the two layer baselayer (called long underwear back then), when I was a kid (if not before I was born), although their inner layer was (horrors!) cotton and the outer was ordinary wool (the itchy kind).
While Merino sheep (originating in Spain) have been around for many centuries, it's only recently that their wool has become so popular. Wonderful stuff, merino wool.
A couple problems with polypro (the miracle fabric of the 1980's for those not old enough to remember)--first of all, it couldn't be dried in the dryer--even at the lowest heat it would melt and then become stiff and harsh. Second, it was a magnet for body odor, which clung to it permanently, despite vigorous attacks with bleach and baking soda. I wonder if this outfit has been able to overcome these problems?