Flat Rim. The outermost element of any side of a numismatic or medallic item that is raised from the background or matrix with a perfect 90° to the edge. A flat rim is in contrast to an oblique border, or to a wire edge.
excerpted with permission from
For Artists, Makers, Collectors and Curators
COMPILED AND WRITTEN BY D. WAYNE JOHNSON
Roger W. Burdette, Editor