Brushed French Terry cotton, layerable, and sneakily warm. This goes well over a tee or a hoodie, color down or flipped up. I don't know how this jacket is as toasty as it is, but if you live in a northern state or your warm weather state has made you soft then this jacket has you covered. Literally. 100% Cotton, 100% Cozy. Note that it is a “cut & sew” knit so specs should be different than woven patterns for same style. Woven garments require more "ease" (extra room) in the pattern for movement because the fabric does not stretch or give like knits. Cut and sew knit garments require less ease because the stretch allows the fabric to conform with body movement. A knit style like this should theoretically be smaller in width specs (negative ease) compared to a woven version of same style to prevent it from looking baggy/sloppy.