The rarest US stamp is up for auction: it will sell for millions of dollars

The rarest US stamp is up for auction. It is expected to sell for millions of dollars. This summer, philatelists will have the chance to acquire the rarest U.S. postage stamp ever: the 1868 one-cent stamp known as the “Z-grill.”

How CNN reportsOn June 14, the one-cent Z-grill stamp will be offered for sale by Robert A. Siegel Auction Galleries, marking the first time the rare stamp has been offered at auction since 1998. Experts at the New York auction house say it could fetch between four and five million dollars, making it the most expensive US stamp ever sold. (It was surpassed internationally by the British Guiana one-cent purple stamp, which sold for $8.3 million in 2021.)

The reason for the exorbitant cost is simple, CNN notes. Of the two known one-cent copies of the Z-grill, one is kept in the New York Public Library. Thus, only one Z-grill with a denomination of one cent is available to private collectors. Since 2005, the coveted brand has been owned by billionaire investor and “bond king” Bill Gross.

“It is considered a trophy of United States stamp collecting,” said Charles Shreve, who for years managed Gross’s extensive stamp collection and is director of international auctions at Robert A. Siegel Auction Galleries.

To the untrained eye, the blue one-cent Z-bar stamp, featuring the nation’s first Postmaster General, Benjamin Franklin, looks like any old stamp. What’s special about it is the raised “waffle” pattern on the paper, also known as the Z-grid.

This piece has a fascinating history. After the Civil War, the U.S. Post Office “developed an irrational fear” of people destamping and reusing stamps, which would in turn result in lost revenue, Scott Trepel, president of Robert A. Siegel Auction Galleries, told CNN.

One way to prevent stamp counterfeiting was a technique called grilling, which created a pattern of small indentations on the surface of the paper. Once the stamp was cancelled, ink would seep through these depressions into the stamp, making it difficult to reuse.

“Is it like a lot of other cheap brands? Yes, at first glance, it looks like an ordinary brand,” Trepel said. “But it’s that grille that makes it so important.”

One-cent stamps were produced in 1868. The stamp hit the market in 1975, selling for $42,500, and again in 1977, this time for $90,000, 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 one-cent Z-grill was put up for auction again in 1998.

Gross, co-founder of Pacific Investment Management Company (PIMCO) and a lifelong philatelist, approached Charles Shreve to help him assemble a complete collection of all stamps issued by the United States Postal Service.

He inherited this hobby from his mother, who began collecting stamps when Gross was a child. According to Shreve, she believed they would increase in value and bring in enough money to pay for his college education. When the collection proved useless, Gross could not forget the dejected expression on his mother’s face. So he decided to prove her theory. “When he started making money, he said to himself, ‘I’m going to prove that my mother was right in buying stamps. She just bought the wrong ones,’” Shreve said.

According to Shreve, the one-cent “Z grill” stamp was one of the last that Gross needed to achieve his goal, but he ultimately lost the 1998 auction to fellow stamp collector Don Sandman.

In 2005, Gross finally acquired a one-cent Z-grill, purchasing a block of inverted Jennys for $3 million and trading it with Sandman for the valuable stamp, finally adding to his collection.

Once Gross achieved this goal, he ventured into collecting other rare stamps before eventually losing interest. He started selling some of them in 2007, but stuck with his beloved U.S. stamp collection until about 2017, when he told Shreve he was willing to sell that, too.

The cost of the entire collection is estimated at 15-20 million dollars. The top 100 stamps from the collection will be auctioned on June 14, while the remaining stamps will be sold on June 15.

“There are a few stamps that will bring $500,000 or $750,000, but the one-cent Z-grill is the star of the show,” Shreve said. “I just know some people who are hungry for it, and we want to try to get as many people interested in it as possible.”