6 specimens illustrating mode of preparing dies for the coinage, struck by William Wyon R A, for the Museum of Economic Geology in illustration of the mode of preparing dies for the coinage, 1842, mounted on mahogany board

These specimens illustrating the method of preparing dies for medals or coins, were made by William Wyon RA, chief engraver at the Royal Mint.

The engraver first produced a steel master die, in intaglio, known as the matrix; this was hardened and used to produce, by pressure, a reversed copy called a punch, the steel being frequently annealed during the process. This punch then served to make any number of working dies, in a similar manner, dates and lettering being put on these by hand. In modern practice the matrix is produced, by pressure, from a master punch made on an engraving machine.