Top 100 Errors / Variations and the state of collections these cards prior to 1985

[steve B]

For stuff like the double prints I like the term Varieties.
It's used in one of my other hobbies to describe an item that's not a correction, but typically a constant error that's a difference in the plate at a particular spot.

There are then specific terms for exactly what the heck went wrong.... Double transfer, Foreign entry, plate scratch, Rust hole, erasure, plate crack, (and that's just for the engraved ones.. typographed and lithographed have their own list of problems.

Collectability depends on how rare or spectacular that variety is, rare AND showy = expensive.