EvaDane - Funny Quotes - Let us pause now for a moment of science - T-Shirts - Adult Birch-Gray-T-Shirt Medium (ts_149870_19) Adult and youth sizes are a blend of 50% cotton, 50% polyester. Toddler sizes are 100% cotton. Available in white, grey, light blue or pale pink. Custom printed image applied. Washing instructions: Do not use bleach, dry on low heat, turn inside out