Definition: In this rare die deformation error, the die face expands during the press run.  In lateral view, it comes to resemble the battered handle of a rock chisel.  Eventually the die face expands beyond the working face of the collar (presuming the hammer die is involved).  The result is that the face of the coin struck by the deformed die lacks the design rim and the peripheral design elements are cut off.

Among domestic coins, design creep has only been seen in a single run of 2014-P nickels, all of which were discovered by Robert Scheschuk.

The reverse face of this 2014-P nickel (struck by the hammer die) shows the effects of design creep.  The design rim is absent and peripheral letters are cut off along the coin’s edge.  This effect is more severe along the southern arc of the coin.  Additionally, the center of the coin displays a peculiar “cottage cheese” texture.  Here the details of Monticello are indistinct.