Metals other than the adopted composition are frequently used to strike hub trials and die trials. They are sometimes struck in copper and white metal. Other times they are struck in softer metals like tin or lead. There are even some examples struck in wax and on cardboard.
There are only 3 known die trials in the entire 20 Cent series.
These trial strikes are listed in the 10th Edition of Judd and also in Pollock. Technically hub trials and die trials are part of the pattern family. However, in the last 5 years the coin market has drastically changed directions.
Many pattern enthusiasts have always wanted a hub trial or a die trial piece to go along with the specific type or denomination of pattern(s) that they collect. A new demand has emerged for hub trials, die trials and splashers. Collectors of major mint errors are placing these in their collections because they are unusual, exotic and unique.
Even though they are not mint errors, they are aggressively sought after by people who collect off-metals, broadstrikes, uniface strikes and coins struck on larger planchets. In addition, since many of these hub trials, die trials and splashers are struck from incomplete hubs and dies, the design may be only a partial portrait or with parts of the legend and date missing.
This uniface die trial shows UNITED STATES OF NORTH AMERICA on the obverse with the date below. It is struck in white metal with a plain edge. This very rare 20 Cent die trial has a famous pedigree since it is Ex Nagy, and Ex Kosoff. It is also the plate coin on page 305 in the 10th Edition of United States Pattern Coins.