NNP

Champs Levée.  A method of reducing certain projection's height in a die, in effect making the depth of some relief shallower in the struck piece; the term is French. Minute projections on a die – like the centers of O and D in lettering or the open area loops in A, P and R, or 6, 8, 9, for example – or any other tiny background areas are most liable to breaking during long press runs. These projections are subjected to great stress and susceptible to breaking off, causing a filled letter mint error in the struck piece.

Champs levée (French, literally: filling open areas) is an attempt to prevent these projections from breaking off by lowering (thus strengthening) the projection in the die. Such tiny projections are ground down in the master die or working die so the relief is not as deep in the struck piece. The human eye would not perceive the shallower depth; the figure or letter O will continue to have the same configuration as before, of course, it will just have a shallower center. (When champs levée is carried to an extreme, it appears the lettering is placed on a raised plane; an example of this was the Louisville Medal struck by Medalcraft of Wisconsin.)

In effect the champs levée procedure (first employed at the Paris Mint) is an

attempt to correct, perhaps, a situation in modeling where the problem could be eliminated by a change of modulated relief. Designers of coins and medals should be aware of these possibilities and eliminate tiny tall projections in their designs for die-struck pieces. There are other champs levée procedures also of grinding down relief to aid dielife while still retaining sharpness and visibility of design as before.

References:                                                                                                                               

C46 {1964} Lauth.

C66 {1988} Cooper p 168.

Change of Polarity.  By adjusting the gears on a modern reducing machine the die can be made in contraposition to the model (that is, a portrait facing right can be changed to face left). Unfortunately everything on the model changes polarity; lettering in the new design will appear as retrograde lettering. (In the die it will appear correct as being read left to right, instead of the negative the die should read; diesinkers call this wrong reading and right reading.)  Portraits are ideal for changing polarity, however, because they look "correct" facing either direction.  See Illustration, contraposition; see also pantograph.

CLASS 04.3

1380-(012)04.3

excerpted with permission from

An Encyclopedia of Coin and Medal Technology

For Artists, Makers, Collectors and Curators

COMPILED AND WRITTEN BY D. WAYNE JOHNSON

Roger W. Burdette, Editor