We love shirt jackets made from heavy, warm materials like wool — but that's not the only option here. Exhibit A: this handsome shacket made from an ultra-light, water-repellant material stuffed with PrimaLoft insulation, which brings lots of warmth, but very little weight. A button-snap front, insulated zip hand pockets, and penty of stretch woven throughout make this a true no-brainer for all-season wear.