Cole Haan Men's 3 Pack Flat Crew Sock Front: 46% Polyester/34% Nylon/20% Cotton; Middle: 60% Polyester/30% Nylon/10% Cotton; Back: 50% Polyester/29% Nylon/21% Cotton Imported Machine Wash This sock can also be worn as a casual sock with jeans or khaki pants Polyester has excellent wash ability. Cotton is soft and heat resistant. Cotton absorbs moisture from the foot and is breathable. Cotton also provides shock absorbency.