High-grade thick fabric with quality construction. 170 lbs, 43" chest, 42" around widest section of belly. 2XL is perfect fit for my liking--arms are snug, and body is non-compression comfort fit with plenty of room for layers without being overly loose and baggy. I bought a second in another color.
with or without additional layers
This Castelli Fondo jersey is size XL for a 66 year old 6' 180 lb person. The fit is very comfortable, sleeves are a proper length and the pockets are well sized and placed. I wore it today for a 17 mile ride at 60 degrees with a wind breaker, short bib and was comfortable. I am pleased with it and would buy another.