The Inverted Jenny (also known as an Upside Down Jenny, Jenny Invert) is a 24 cent United States postage stamp first issued on May 10, 1918, in which the image of the Curtiss JN-4 airplane in the center of the design is printed upside-down; it is one of the most famous errors in American philately. Only one pane of 100 of the invert stamps was ever found, making this error one of the most prized in philately.