Essential Oils t-shirt Keep Calm and Diffuse On Solid colors: 100% Cotton; Heather Grey: 90% Cotton, 10% Polyester; All Other Heathers: 50% Cotton, 50% Polyester Imported Machine wash cold with like colors, dry low heat Essential oil lovers will adore this keep calm shirt. Perfect for those that have an oil for everything! Lightweight, Classic fit, Double-needle sleeve and bottom hem