In 2013, they reissued the famous stamp, selling them ... they decided to print the stamps upside down on purpose–but also created 100 sheets with the airplane flying right side up in an attempt ...

The "Inverted Jenny," 1918, one of the rarest and most valuable stamps in the world, celebrates the first air mail in the U.S.—by depicting an inadvertently upside-down airplane. Hannah Whitaker ...