Mis-struck
Mis-struck. A medal or coin made from a broken, damaged, impaired or misaligned die, from a defective or improperly positioned blank, or an incorrectly struck piece. A wide variety of striking flaws can occur (distinct from planchet flaws, errors in the die, and finishing flaws). Striking flaws include: die trial, misaligned die, double and multiple strikes, collar errors (clashed collar, missing collar, broken collar), brockage, cupping, indented and impressed errors, off center strikes, filled die, rotated die, and incorrect mating of obverse and reverse dies (muling). Correct striking is the responsibility of the pressman and the pressroom foreman, any mis-struck pieces should be caught by inspection (but, obviously, mis-struck pieces slip by inspectors). See errors, inspection.
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