PART VI. Striking Errors:

Capped Die Doubling:

Shifted Cap Strike:

Definition: A coin struck through a late-stage die cap that has become dislodged and shifted out of position.  It generally produces a set of incuse, normally-oriented design elements, i.e., ones that face the same way as their normal raised counterparts.

A late-stage die cap molds itself to the recesses of the die face.  The floor of the cap is thinnest where it overlies the field portion of the die face.  The cap floor is slightly thicker in the recesses of the die face because effective striking pressure is slightly lower there.  When a die cap shifts out of position, those slightly thicker areas are driven into the next planchet, producing the normally-oriented, incuse design elements.

A die cap can rotate, shift laterally, or both.  The 1990 cent shown here was struck through a die cap that shows a combination of movements.

This 1990 cent was struck once through a late-stage obverse die cap. The cap had rotated 180 degrees and shifted laterally to the north immediately before it struck the planchet represented by this coin.  An extensive set of normally-oriented incuse design elements overlies the strong ghost of Lincoln that bled through the cap from the obverse die.  A sunken arc at the southern pole of the obverse face marks the “zone of collapse” where the wall of the cap was telescoped and crushed into the planchet.