PART III. Die Installation Errors:

Mismatched business / proof dies:

1956 -1964 quarters with “Type B” proof reverse

Definition: Subtle differences in design details often differentiate dies intended for business strikes and those intended for proof strikes. The accidental preparation of a business strike die as a proof die is a well-known phenomenon. Examples include the 1998-S and 1999-S proof cents with the “Close AM” reverse.

Between 1956 and 1964 Washington quarters, both business strikes and proof, can be found struck with mismatched dies. Type A was typically used on business strikes, while Type B was normally used on proofs. All years between 1956 and 1964 are known to have either reverse; with proofs scarcely having a Type A and business strikes scarcely having a Type B.

Type A: has a close ES in STATES; the A is not connected to the leaf above; and the leaf west of the arrows is below and lower in relief.
Type B: has a wide ES; a connected A to the leaf; and the leaf west of the arrows is higher and in stronger in relief.
Type C, found on 1965 quarters is here for reference as some 1964D quarters have been found with that reverse.