Jenny (or Jenny Invert) is a 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 was accidentally printed
upside-down; it is probably the most famous error in American philately. Only
one pane of 100 of the invert stamps was ever found, making this error one of
the most prized in all philately; an inverted Jenny was sold at a Robert A. Siegel
auction in November 2007 for US $977,500. In December 2007 a mint, never hinged
example (one not previously affixed to a stamp album), was sold for $825,000.
The broker of the sale said the buyer was a Wall Street executive who lost the
auction the previous month. A block of four inverted Jennys was sold at a
Robert A. Siegel auction in October 2005 for US$2.7 million.