Base, mid, shell. In order words, something tight which removes moisture, something like a nano-puff to fill space, and something like gore(tex) outer. You can find breathable jackets combining mid + shell for fairly cheap. Air is the only insulator. Wool is super cruel. It is NOT a simple "haircut" as many would like to believe. Even if it were, not our wool to take. This is fact. Even "responsible standards" are simply "third party certified" which doesn't mean anything in the realm of animal abuse / sustainability / workers rights etc. It's all nonsense. Same with "humane, grass fed, free range" Money is exchanged for those labels to exist. It's an industry - a business. Industry meets minimum requirements on the surface, but undercover investigations prove otherwise. Synthetics are more durable / last longer, dry faster, cost less. We have the ability to be happy and healthy without supporting / voting for the destruction of our natural world.