Mint-made errors are called "type-2 blanks (or planchets)" after an upending mill adds uniform, rounded rims. Type-2 blanks may also be considered striking errors as they are prepared correctly, but are released without having been struck. A misfeed can occur when the metal strip is fed through the blanking machine. The punches sometimes overlap the leading edge of the metal producing a straight clip. Sometimes, the punches strike an area of the strip which overlaps the hole left by the previous strike producing a curved clip. Sometimes punches strike the irregular trailing edge of the metal strip producing irregular clips. Coins are
Eisenhower dollar proof planchets were to be used for uncirculated "blue Ikes", but these were placed in the bin for rejected copper-nickel proof planchets, intended to be shipped to be coined for circulation at Denver. The 1977 pieces resulted from pieces rejected for Bicentennial silver proof use, which were again placed in the wrong bin (they should have been melted, as the Mint was no longer striking silver uncirculated Eisenhower dollars). Between 10 and 20 of each date are known. Wexler, Crawford, and Flynn report an even rarer 1776–1976-D dollar in silver, but state that none have been offered at auction or