Duofold by Champion Thermals Men's Long-Sleeve Base-Layer Shirt, Bordeaux Red 60% cotton 60% cotton (for softness)/40% polyester (for durability) Ideal on its own or as base-layerthermal underwear. Choose thisbase-layer shirtfor everyday warmth during low activity levels. Tag-free banded crewneck won't itch or scratch your neck. Soft texture-rich knit traps air between two thermal layers. Result: a chill-blocking barrier that keeps you comfortably warm.