However, a new state is not necessarily a new edition, since the imprint may not have been changed. A printing process employing a metal plate on which has been scratched a design. When ink is applied to the plate, and the plate wiped, ink remains behind in the grooves. A dampened sheet of paper is laid onto the plate and under pressure the inked design is transferred. A printing process similar to engraving, except that the plate is produced by coating it with an acid resistant material upon which the design is scratched.
Acid is used to eat away at the scratched areas, creating the grooves to hold the ink for printing.
A folio book is bound from sheets of paper folded one time. A map from such a book is sometimes said to be folio-sized. Small, usually brown, spots on the paper caused by mold. Foxing often results from storage in damp conditions. Gores are usually shaped like an American football.