Portal:Philately/Stamp of the month archive/2

Dag Hammarskjöld invert, is a 4-cent value postage stamp error issued on 23 October 1962 by the United States Post Office Department. The stamp, showing the yellow background inverted relative to the image and text, is also known as the Day's Folly after Postmaster General J. Edward Day who ordered the intentional reprinting of the yellow invert.

The stamp reprint of 40 million stamps was a deliberate error produced to avoid creating a rarity and was issued to the public within a month of the original issue date. The discovery sheet was owned by Leonard Sherman, a New Jersey jeweler, who donated his sheet to the American Philatelic Society in 1987 because the reprint dashed his hopes of owning a valuable stamp error.