A die cap error on a 1906 Liberty Head 5-cent coin is the only such error known that is also an off-metal error. The error coin is certified by Numismatic Guaranty Co. as Mint State 65 red and brown, struck on a planchet intended for an Indian Head cent and not a copper-nickel 5-cent coin.

According to error coin dealer Mike Byers from Mike Byers.com in Las Vegas, Nevada, the 1906 obverse die cap error weighs 3.1 grams, slightly less than the 3.11- gram standard for a bronze Indian Head cent, composed of 95% copper and 5% tin and zinc.

A standard planchet for the Liberty Head 5-cent coin would have been composed of an homogeneous alloy of 75% copper and 25% nickel, weighing 5 grams, the same composition as for current 5-cent coins — it has remained the same since the Shield 5-cent coin series was introduced in 1866.

A die cap error is a dramatic coin production anomaly that occurs when a struck coin fails to eject, sticks to the upper hammer die, and acts as a makeshift die face, striking subsequent planchets. Repeated strikes force the stuck coin’s metal upward and outward, resembling a bottle cap or thimble.

According to Byers, another well-known error coin dealer, Fred Weinberg purchased the 1906 Liberty Head, obverse die cap, off-metal error in a collection in 2002 for resale to prominent error coin collector Mark Lighterman, current president of the American Numismatic Association.

Before transferring ownership to Lighterman, Weinberg submitted the piece to NGC for authentication and grading, whereupon NGC graded it MS-66 brown. The piece was authenticated and graded at NGC  by its error coin specialist, David Camire.

Subsequently, the error was submitted to Professional Coin Grading Service and crossed over to a PCGS holder at MS-65 brown. The coin was then submitted to Numismatic Conservations Services (where Camire serves as president) and the coin was re-certified by NGC as MS-65 red and brown.

Lighterman subsequently sold the error coin to another collector, from whom Byers has acquired it.