One can buy wool long-sleeve jerseys & tights to use as a mid-layer or use dress wool or synthetic sweaters. I suppose one would hear more about wool mid-layer except that wool's anti-stink properties aren't as important as with a base layer. Bought an Arcteryx Atom synthetic mid-layer jacket which is super-comfy & light & includes vents/pockets. A bit pricey but more versatile than a wool l/s jersey or sweater.