When I have the option, I prefer wool.

Joe Jackson, writing for Outside Magazine:

There must be hundreds of times that I’ve touted the unparalleled odor-mitigating and moisture-wicking qualities of this wonder material. I stand by the endorsement: For all their capabilities, man-made synthetics are merely trying to mimic what wool does naturally. And for all our technology, nature still does it better. Yet while wool is natural, the myriad ways outdoor companies process, futz with, and incorporate it into apparel can be overwhelming.