Personalized Worlds Best Librarian American Made T-Shirts. Librarian design American Made T-Shirt - White says World's Best Librarian in tan and brown with sports styling. Enjoy the comfort and durability of this 100% cotton t-shirt Born in the U.S.A. 5.4 oz., pre-shrunk 100% cotton. Heather Grey is a cotton/poly blend. Double-needle stitching throughout. . Seamless collar. Shoulder-to-Shoulder taping. Made in America.