Personalized Chemistry Smiley T-Shirt. A smiling yellow face made from chemistry text with the caption Chemistry makes me smile is a humorous chemistry design. Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.