One of the more interesting and difficult to obtain Topps test issues the 1973 Topps Pin-Ups were actually wrappers for large sticks of bubble gum. The front of the pin-up which featured the player"s photograph faced inward touching the gum. The back of the pin-up was actually the outside of the wrapper. Given the collectibility of vintage wax wrappers one wonders why the practice of affixing player images to the inside of card wrappers was discontinued after this test.Represented here is Hall of Fame outfielder Billy Williams of the Chicago Cubs. The pin-up is in excellent shape with sharp corners and a clear image that at first glance would imply a higher grade; closer inspection reveals very mild wrinkling near some corners and slight discoloration along the edges that are consistent with how these cards were distributed - as gum wrappers.A very strong example of a Hall of Famer from one of the more interesting and difficult-to-find Topps test issues from the 1970s.Population data:PSA Population: 8 total graded 2 at this level 5 higherSGC Population: None graded