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Resistant.  A coating to prevent some kind of chemical, or electrical, or physical action from taking place; a stop-off. In making coins and medals resistants are used in electro- lysis, particularly in electroplating, acid etching, proof polishing and patina work. This is accomplished by making the surface nonconductive for electrolysis, or by chemically prohibiting the action, as in acid etching, or physically blocking proof polishing. The rack used in holding medals to be electroplated is often coated with a resistant to prevent it from being plated every time it is inserted in the electrolytic tank. While some physical prohibition can be achieved with resistants, some medal makers prefer to use a jig.  See stop-off.

excerpted with permission from

An Encyclopedia of Coin and Medal Technology

For Artists, Makers, Collectors and Curators


Roger W. Burdette, Editor

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