Ever wondered what the rarest stamp in the U.S. is?
The “Z Grill” is a 1 cent stamp featuring Benjamin Franklin of which only two are known to exist. The Z Grill is considered one of the rarest United States stamps, along with the 15 cent Lincoln Z Grill and the 10 cent Washington Z Grill.
What is a grill, exactly? In philately, a grill consists of an embossed pattern indented in the stamp in order to prevent postage stamp reuse. The ink of the cancel seeps into the indentation, making it more difficult to wash off the cancellation. The specific “Z” pattern put horizontal ridges into the stamp, rather than the usual vertical ridges. The grill process was the standard for postage stamps in the 1860’s and 1870’s.
Only two known 1868 Benjamin Franklin stamps with the Z Grill exist, making them extremely rare. Likely hundreds of thousands of 1 cent Benjamin Franklin stamps were printed, but only two with a Z Grill survived. Both have cancellation marks.
Where are these rare stamps now? The New York Public Library owns one as part of their Benjamin Miller Collection, a collection of rare stamps donated in 1925 by philatelist Benjamin Kurtz Miller.
The other Z Grill rests in a private collection.
In 1998, one Z Grill sold for $935,000 to Mystic Stamp Company. Later, the stamp was traded to Bill Gross for a block of four Inverted Jenny stamps worth $3 million. As a result, Gross became the only owner of a complete collection of American 19th century stamps.