Personalized Worlds Best Chemist Long Sleeve T-Shirt. Great looking gift for the chemist, chemistry professor or chemistry major, this Worlds Best Chemist gift Long Sleeve T-Shirt - Black with blue and tan logo is a unique way to show you love them. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL