The Women's Patagonia R1 Fleece Vest is made with durable, stretchy, and breathable Polartec Power Grid fabric, hybridized with Capilene Thermal Weight baselayer fabric to reduce bulk and enhance lightweight performance, while HeiQ Pure odor control helps maintain freshness. The hybrid design increases warmth around the chest and shoulders while promoting breathability and heat venting at the back and underarms. Fabrics deliver excellent stretch and mobility, and the slim fit with a center-front zip and low-profile zipper garage at the chin ensures next-to-skin comfort. A low-bulk hem allows for smooth layering, and low-profile shoulder seams offer chafe-free comfort under a pack.