Patagonia designed Capilene Cool Trail, their softest performance knit, to keep you cool and dry when you're active, while providing day-long, next-to-skin comfort. Quick to wick moisture and quick to dry, Capilene Cool Trail feels like cotton yet performs with the wicking efficiency of polyester for running, biking, travel or all of the above in the same day. Made of 4-oz 100% polyester spun jersey, this tank has a soft hand, a light weight and Polygiene permanent odor control so you stay welcome among friends at the end of the day.