PART V. Planchet Errors:

Bonding / Bonding Mill Errors:

Missing Clad Layer:

Partial:

After Strike

Definition: A portion of the clad layer separates from the coin after the strike.  Exposed design elements are
characteristically mushy.  Loss of the clad layer is due to a failure for this portion of the clad layer to fuse with
the core in the bonding mill.  Inadequate cleaning of the core and clad strip may be responsible.

This 1972-S Proof Eisenhower dollar had part of the clad layer (80% silver, 20% copper) on the reverse face split off after it was struck.

Images are courtesy of Heritage Auctions.