Duofold Midweight 2 Layer Ankle Bottom Womens 100% cotton base-layer-underwear closure Fit: Relaxed--Full cut for ease of movement and versatility in layering. Fabric Type: Thermal--A loosely woven fabric that allows air to circulate and body heat to escape Flatlock Stitching--Seams are sewn flat to the garment to enhance durability and prevent skin chafing/irritation. Fabric Content: Exterior: 65% cotton, 25% Merino wool, 10% nylon Fabric Content: Interior: 100% cotton