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Fill-in.  Coloring an incuse area – as lines forming letters, figures and ornaments engraved or inscribed on a medallic item – to form a contrasting color to increase the legibility of the lettering or design. This occurs only on an existing medallic item, that is, one already finished (should such inscribing be done on an unfinished medal, the normal finishing process would automatically highlight the incuse lettering).

Types of fill-in.  There are four types of fill-in, each with a different method of application:  (1) monogram filler is rubbed over the incuse area a number of times at room temperature, its crayon-like material filling the area; (2) lacquer sticks are rubbed over a heated object, the colored lacquer melts and fills the incuse area; (3) champlevé enamel in colored granules is poured into the sunken area until it fills the channels, the object is then heated until the enamel melts, then solidifies on cooling; (4) enamel paint is brushed or sprayed into the incuse detail where desired and the excess is wiped off while still wet.

Because each of these are below the object's surface they are not susceptible to chipping – unless, perhaps, a sharp pointed blow occurs inside the channel. Champlevé is the most permanent; monogram filler the least (which can be removed with benzine).

Any color can be applied by any method of fill-in. Since these are applied to brown (bronze), gray (silver) or gold medals, a color in contrast to these is usually chosen. Black and red are the most used colors in 20th century medallic art, but commercial colors are available also in white, blue, green, orange, yellow, silver and gold.

Fill-in is applied to a metal surface that is hand or machine engraved or inscribed, or even part of the diestruck or cast design. The item can be lacquered afterwards irrespective of any previous lacquering.

An early form of medallic engraving – niello – utilized a composition of copper, lead and sulfur in borax to fill-in the finely engraved lines of this technique. The object was heated and when cooled the hardened black filler was polished to contrast with the bronze or silver item.

Cataloging. When medallic items are found with fill-in they should be identified as such when cataloging. If possible the kind of fill-in substance should be identified:

enamel, wax, niello. Otherwise the statement letter fill, or monogram filler should be used.

Fin.  A sharp protruding ridge at the rim/edge juncture where excess metal squeezes out between the dies and collar on a piece struck in a coining press; flash on a coined piece.

A pressman would call it a BURR and attempt to remove or remedy it; a collector might call it by an obsolete term such as WIRE EDGE in America, or a KNIFE EDGE in England. It is caused by a mismatch between die diameter, collar and planchet diameter. This can occur due to a worn collar, excessive pressure, improper upset angle and planchet dimension, an oversize or overweight blank or simply, sloppy presswork. The pressman needs to make some immediate adjustments because such fins create problems in ejecting coined pieces. It is more apt to happen on proof coinage, but is not diagnostic of proof coinage as it can occur in any coining operation. Such fins can be removed by CHASING if the pieces cannot be struck anew. The goal of every pressman should be to coin pieces with sharp edges, this is, with 90° angles at the RIM/EDGE JUNCTURE without any FLASH at all.

CLASS 08.1


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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