Under Armour Boys' Big Flag Logo 57% Cotton, 38% Polyester, 5% Elastane Under Armour mission is to make all athletes better through passion, design and the relentless pursuit of innovation Where we started? It all started with an idea to build a superior T-shirt Under Armour's assortment for men, women and youth is complex, but reaping the benefits is simple: wear HeatGear when it's hot, ColdGear when it's cold, and All Season Gear between the extremes