Z Grill

The rarest American stamp is a plain 1 cent Benjamin Franklin of 1868, set apart only by its grill, a pattern of tiny points embossed into the paper so cancellation ink would soak in, of the rare type collectors label "Z." Two copies are known. One, from Benjamin Miller's collection, belongs to the New York Public Library. The other is the story. In 2005 the bond investor Bill Gross, one stamp short of a complete 19th century US collection, traded an Inverted Jenny plate block for it. In June 2024 it sold to an anonymous buyer for $4.366 million. Few stamps show so clearly how a collector's need for one empty space can drive a price.