Filler
Filler. A collectors term for a specimen in low condition intended to be replaced by a better specimen at a later time. Since items in collectible condition should be easy to obtain, fillers are usually of varieties of extreme rarity. Thus it is better to have some example of a rare variety than none at all.
excerpted with permission from
An Encyclopedia of Coin and Medal Technology
For Artists, Makers, Collectors and Curators
COMPILED AND WRITTEN BY D. WAYNE JOHNSON
Roger W. Burdette, Editor