Note 1 — Chapter I

At the present day line engravers sometimes work on steel plates, as they are capable of supplying without damage a much greater number of proofs than can be printed from copper plates. It more frequently happens that a copper plate is coated with steel before being submitted to the action of the press, in order to preserve it, and to increase the number of copies without taking off the edge of the workmanship. That is to say, that by means of "electrotyping" a thin coat of metal is superimposed, which, since it considerably increases the power of endurance, increases the productiveness of the plate and the number of proofs that can be taken.