This is a silvered electrotype medal copied in the 19th century in England, of a 17th century original. The obverse of this medal represents the bust of Prince Rupert holding a marshal's baton. The reverse shows the arms of the Prince with the letters R. P.
The method of Electrotyping was invented by Moritz von Jacobi in Russia in 1838. It has complemented the older form of stereotyping. A mold is made, often of wax and then coated with very fine graphite powder or paint. The mold will then be suspended in an electrolyte solution.
In printing electrotypes are used instead of the original for long press runs, to avoid wear and damage to expensive type and linecuts. Electrotypes also can duplicate and replace linoleum cuts, woodcuts, and wood engravings and are used to duplicate metal sculpture. In the 19th century, museums often displayed electrotypes of ancient coins instead of the originals and individuals purchased electrotypes for their private collections.