Collection from Goudey Gum's large (5"x7") series of R303 premiums printed in black, including Feller (HOF), Goodman, Higgins, Keltner, and York. Goudey offered these rough paper "cards" as an in-store exchange for baseball pack wrappers to encourage customer loyalty.
The educational art on R303 backs originated with National Chicle's 1936 R344 "How To" booklets. Recent research indicates Goudey repurposed these diagrams to promote their sale of surplus "Diamond Stars Gum" baseball packs acquired in the bankruptcy sale of crosstown competitor National Chicle.