Wool
Wool is a high performance material, giving outdoor enthusiasts many advantages.
Naturally, wool offers at least 10% more breathability to the wearer compared to other performance designed materials derived from synthetics. Wool is naturally water resistant, and next to waterproof and windproof when made in the boiled wool method. When wet, wool still insulates, unlike down filled insulative layers. Wool is extremely durable, naturally rugged in tough mountain environments.