|
It will be seen at once that the working die is, in allrespects, similar in function to the steel printing plateand performs the same function—namely to print stamps.It differs only in that the working die consists of a singledesign whereas the printing plate has many subjects.After proper hardening the working die is placed in theprinting press, or envelope-making machine. Directlyopposite the die there is a resilient substance, such asleather, against which the die strikes. The surface of thedie is inked, the paper placed between it and the resilienttympan, and the operation of printing and embossing iscompleted when the press strikes against the tympan.This striking can be either by direct downward or up-ward pressure or by a rotary motion. In any case thepressure is sufficient to force the paper hard enoughagainst the engraved recesses of the die to transfer theselines to the paper. |
|||
|
