Here is something just for serious stamp collectors. This summer, philatelists will have the chance to get their hands on the rarest U.S. stamp of all time: the 1868 “Z-grill” one cent.
Interested? It will cost you (more than) a pretty penny.
On June 14, Robert A. Siegel Auction Galleries will put the one-cent Z-grill up for sale, marking the first time this rare stamp has come up for auction since 1998. Experts at the New York auction house say it could reach a selling price between four and five million dollars, which would make it the most expensive American stamp ever sold. (It is surpassed internationally by British Guiana’s One-Cent Magenta, which sold in 2021 for $8.3 million.)
The reason for the exorbitant cost is simple. Of the two known copies of the Z penny grid, one is located in the New York Public Library. That leaves only one penny Z grill available to private collectors. Since 2005, the coveted seal has been owned by billionaire investor and “bond king” Bill Gross.
“It’s considered the trophy of American stamp collecting,” said Charles Shreve, who has managed and built Gross’s extensive stamp collection for years and serves as director of international auctions at Robert A. Siegel Auction Galleries.
“There’s only one. If you want to show off, that’s the seal.”
What’s so special about a Z grill?
To the untrained eye, the blue Z-shaped grid on a penny, depicting the country’s first postmaster general, Benjamin Franklin, looks like any old stamp. What sets it apart is the waffle pattern etched into the paper, also known as the Z grill.
The detail has a fascinating history. After the Civil War, the United States Post Office “developed an irrational fear” that people would clean and reuse stamps, which in turn would contribute to a loss of revenue, Scott Trepel, president of Robert A. Siegel Auction Galleries.
One of the ways they sought to prevent stamp fraud was through a technique called grilling, which created a pattern of small indentations on the surface of the paper. Once the stamp was cancelled, ink would leak through those notches in the stamp, making it difficult to reuse. The Z grille, although uncommon, was one of several grille patterns.
“Does it look like a lot of other cheap stamps? Yes, at first glance, it looks like a regular stamp,” Trepel said. “But that grill is what makes it so important.”
Lots of history behind
One-cent Z grills were produced in 1868. According to Trepel, this particular one was discovered in 1916 and resurfaced in 1957. The stamp hit the market in 1975, selling for $42,500, and again in 1977, this time selling for $90,000. dollars, according to the auction house. It was eventually acquired by Los Angeles Lakers owner Jerry Buss, who sold it in 1986 for $418,000.
The penny grill Z was auctioned again in 1998.
Gross, co-founder of Pacific Investment Management Company (PIMCO) and a lifelong philatelist, had hired Charles Shreve to help him assemble a complete collection of every stamp issued by the United States Postal Service.
He got his hobby from his mother, who started collecting stamps when Gross was a child. According to Shreve, she believed they would increase in value and produce enough money to pay for her college education.
When the collection proved useless, Gross couldn’t forget the dejected expression on his mother’s face. So he set out to test his theory.
“When he started making money, he said to himself, ‘I’m going to prove my mother right about buying stamps. She just bought the wrong ones,'” Shreve said.
The one-cent Z grid was one of the last stamps Gross needed to achieve his goal, but he ultimately lost the 1998 auction to fellow stamp collector Don Sundman, Shreve said.
In 2005, Gross finally acquired the penny Z grill by purchasing a block of Inverted Jennies for $3 million and trading it to Sundman for the prized stamp, finally completing his collection.
Once Gross achieved that goal, he ventured into collecting other rare stamps before losing interest. He started selling some of them in 2007, but kept his beloved American stamp collection until about 2017, when he told Shreve that he was ready to sell it, too.
The entire collection is estimated to be worth between $15 and $20 million. The top 100 stamps in the collection will be auctioned on June 14, while the remaining stamps will be sold on June 15.
“There are several stamps that will make $500,000 or $750,000, but the Z grid (one cent) is the star of the show,” Shreve said. “I only know a few people who want it and we want to try to get as many people interested in it as possible.”