Personalized Border Collie Dad (Worlds Best) T-Shirt. Border Collie dog Dad T-Shirt - Athletic Heather with paw print world's best logo in tan and brown. 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.