I've been looking at insulating layers, and I have all kinds of fleece, but I remembered that when I went to Glacier Nat. Park a few years back, I used a fairly thin black cashmere sweater underneath my North Face shell, and it was amazingly warm and lightweight.
I'm looking at the weight of all of my fleece options, and their warmth factor, and the cashmere is looking like a winner.
Does anybody still wear wool as their insulating layer anymore? Has fleece taken over completely?