Personalized Worlds Best Biologist T-Shirt. Buy a fun World's Best Biologist T-Shirt - Light Blue as a gift for a biology major, biologist, biology teacher too. Great looking sports style logo in navy blue and tan. Everyone loves our Custom T-Shirts! 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.