Personalized Big Sister T-Shirt. Big Sister apparel and gifts. Click on the tabs to choose the product, size, and color that you wish this design to be printed on. 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.