So Relative! Super Big Brother Super Hero Baby-Boys & Kids T-Shirt What kid doesn't love cool t-shirts? Surprise the big brother to be with this fun tee guaranteed to bring smiles to everyone who sees him! Brand new 2015 design! Read all the bullets below for specific sizing information. These are 100% heavyweight cotton shirts (Sport Grey is 90/10 Cotton/Polyester.) They are professionally screenprinted with environmentally-friendly waterbased ink. They do run a little small. Please consider ordering a size up. Toddler sizes are true to size. Youth sizing is as follows: Youth X-Small (2-4); Youth Small (6-8); Youth Medium (10-12); Youth Large (14-16); Youth XL (18-20).