VOCABULARY TERMS: REVERSE PROOF, SHADOW

Reverse Proof. A proof finish of the entire coin or medal's surface with reflective mirror-like surface on the devices and lettering only with background or field in a satin matte finish. It is the "reverse" of the customary cameo proof where the devices are satin matte, and background is proof polished (because this area is highest in the die, it is easiest to proof polish).

The Royal Canadian Mint was first to issue coins in reverse proof in 1981. It struck gold Maple Leaf bullion coins that year with the new proof polishing technique, calling it "brilliant relief on a satin background." Other countries followed – Great Britain, Austria, Australia – and the United States in 2006. The choice of the two proof surfaces are to give contrast to each other on the same side of a coin or medal.

Reverse Shadow. A light reflective area on tin and high tin alloys, including pewter and some white metal struck pieces caused by surface displacement during striking. This is an unusual property of coining metallurgy where the surface will not tone but becomes lighter and reflective than adjacent areas. Tin compositions do not work harden in certain areas where the flow marks will continue to be bright while the remainder of the surface will darken by toning. Usually lettering (because of the stress in forming these) will exhibit this bright reverse shadow effect. The surface tones in time, the stress area remains bright, forever! Evidence of this "negative shadow" is a diagnostic that the composition is high in tin content.

To read the complete entries on the Newman Numismatic Portal, see:
Reverse Proof (https://nnp.wustl.edu/library/dictionarydetail/516646)
Reverse Shadow (https://nnp.wustl.edu/library/dictionarydetail/520557)

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