Solid color: 100% cotton. Ash Heather color: 98% cotton / 2% viscose. Oxford Grey: 90% cotton / 10% viscose. Colors Wine Heather; French Navy Heather; Green Marble Heather; Cloudy Blue Heather: 80% cotton / 20% polyester. And the color Grey Heather: 70% cotton / 30% polyester. All color combinations are made of converting organic cotton. Combed cotton. Ribbed round neck with elastane. Matching neck cover seam. Tubular. Double stitch finish on the bottom of sleeves and garment.