DIE CUTTING

Dies,[41] generally required for stamping the covers of books in gilt

letters and designs, are cut in brass by hand or by finely adjusted

routing-machines, the design being drawn upon the metal by an artist,

or transferred to it by photography. In the case of very elaborate

designs, the dies are first etched by nitric acid or iron perchloride,

and the more open or less intricate spaces then deepened by hand, or by

the routing-machines.