Editor's note: This is one in a series of Coin World Collector Basics posts on numerous types of planchet errors.

Laminations

During the preparation of the planchet strip, foreign materials — grease, dirt, oil, slag or gas — may become trapped just below the surface of the metal. Coins struck from this strip later may begin to flake and peel since adhesion is poor in the location of the trapped material.

The Jefferson, Wartime 5-cent pieces are particularly susceptible to lamination, due to the poor mixing qualities of the metals used during the war metal emergency.

More planchet error basics:

• Split planchet errors differ depending on when split occurs
• Fragment errors result when scrap coinage metal is struck

Check back with CoinWorld.com for more Collector Basics!