1948 Topps Magic Photo Christy Mathewson

I bet some of you didn't know that Topps actually began producing baseball cards in 1948.

This card is tiny, about the size of a postage stamp.

My understanding is that when getting the card it was actually blank. After reading the clue on the back, you would wet the front of the card and hold it up to the sun. And sure enough, the photograph would develop.

This card happens to be of Hall-of-Famer Christy Mathewson. As you can see by reading the card's back: Mathewson pitched three shutout innings against the Philadelphia A's in the 1905 World Series.

He was one of the original five to be enshrined in Cooperstown, N.Y.

CORRECTION: Three shutouts, not three shutout innings. Thanks for catching my mistake.