What is Die Abrasion Doubling?

Definition: Die abrasion doubling is a hypothesized form of image doubling on coins that is often confused with die deterioration doubling. According to leading error coin expert and CONECA President Mike Diamond, the concept of a coin die striking doubled images as the result of abrasion (die polishing) hasn't been proved. The die abrasion doubling notion claims that when the Mint workers polish the die faces during routine die maintenance, improper or repeated polishing can damage the inscriptions and devices on the die to the point that they can appear doubled on struck coins. The real cause of this distinctive type of doubling is probably deterioration of the dies.

See also:
Die Deterioration Doubling
Doubled Dies
Mechanical Doubling