PART IV. Die Errors:

Die Deterioration / Deformation errors: 

Die Deterioration Doubling

Definition: Die deterioration (die wear, die fatigue) sometimes produces discernible doubling of affected design elements.  We call this die deterioration doubling (DDD).  Its appearance is highly variable.  It is often raised but can sometimes be incuse.  Incuse DDD is most often seen on copper-plated zinc cents, but does occasionally appear in other issues.  Die deterioration doubling may completely surround an affected design element (like a number or letter) or may be restricted to one side.

The images below shows die deterioration doubling on a 1955 Lincoln (raised), Jefferson nickel (raised) and 1989 Lincoln (incuse).