What is a Shirtjac? Quite simply it's a shirt-jacket combo that makes an excellent work shirt and layering piece. Get the best of both worlds with a responsibly sourced down filled jacket that wears like a shirt. Pop-up rain showers? We’ve coated this lined shirt with a durable water repellency to help keep you dry. Easily accessible snap closure pockets are on the chest and on the interior chest. Side entry hand pockets with quick-dry fleece lining to keep your hands warm when you need to lean more into the “jac” side of this piece.