Chattering. A working loose and rapid vibration of a die or dies (within their chucks) during a long striking run. Dies often rotate while chattering causing the struck pieces to lose their proper die alignment. Chattering is a major cause of rotated die error, and such pieces may show double image on one side only (from the die that has worked loose). This double image may appear only on small areas of relief, as letters and figures, as mechanical doubling. Here the movement of the die occurs as twisting while the die is being withdrawn and pulls a portion small relief from its fixed position, leaving heavier relief, as portrait or device, unaltered.Chattering is only caught by a pressman's inspection and realizing what has happened. It is cured by his stopping the press, tightening the set bolts in the chucks holding the dies in position, and restarting the press.Collecting coins with rotated dies is an interesting numismatic pastime but it cannot be determined from the struck piece itself if it was called by chattering, or bythe improper alignment of dies during setup.
excerpted with permission from
For Artists, Makers, Collectors and Curators
COMPILED AND WRITTEN BY D. WAYNE JOHNSON
Roger W. Burdette, Editor