Merino Smartwool. Light weight base layer, medium over that, heavy Filson over that if needed Filson wool zip front vest over that Filson jacket liner with sleeves over that. Any combo of the above great flexiblity and movement. The last layer restricts movement a little but not as much as a single heavier garment. Layering deals with wind pass through pretty well. For warm early seasons you can go with just a single light weight or medium layer with cotton camo on top if you think you need it.