A shirt jacket with a laidback design and the comfort of 100% sherpa fleece. It looks equally great on its own or worn unbuttoned over a tee. Be sure to add this versatile garment to your chilly weather kit. This cozy shirt — even more jacket — is just the ticket. Handy chest pockets, while a straight hemline make for easy layering, worn as a jacket. Columbia offers this men’s shirt-jacket in multiple colors and sizes. Regular Fit. To ensure the size you choose is right, utilize our sizing chart and the following measurement instructions: For the sleeves, start at the center back of your neck and measure across the shoulder and down to the sleeve. If you come up with a partial number, round up to the next even number. For the chest, measure at the fullest part of the chest, under the armpits and over the shoulder blades, keeping the tape measure firm and leve.