Champion Duofold Thermals Men's Long-Sleeve Base-Layer Shirt 6-oz. 60% cotton (for softness)/40% polyester (for durability) Imported Soft texture-rich knit traps air between two thermal layers. Result: a chill-blocking barrier that keeps you comfortably warm. Soft texture-rich knit traps air between two thermal layers. Result: a chill-blocking barrier that keeps you comfortably warm. Tag-free banded crewneck won't itch or scratch your neck. Non-chafe flat-locked seams feel soft against your skin. Ideal on its own or as base-layer thermal underwear.