Its commercial job-plate department is a separate and distinct unit from the newspaper advertising-plate department.
The character of the respective requirements of commercial job-plates and newspaper advertising plates make this departmental production advisable.
A lead-molding press, built by The F. Wesel Mfg. Co., weighing over thirty-thousand pounds, and developing two thousand tons pressure per square inch on a thirty inch hydraulically operated ram is used in the job-plate department. On this press are duplicated, from the finest screen half-tones, the highest quality electrotypes and nickeltypes to be used in three and four color process printing.
The preponderating volume of its business, however, is the production of newspaper electrotypes, and it is in this department that The Rapid Electrotype Company has made distinct improvements in manufacturing practice by methods and machinery designed and constructed by its own engineers in its own machine shop.
BLACK LEADING
The Rapid Electrotype Company has built a new type of machine for use in this important phase of the electrotyping art. It is a combination Dry-Wet Machine, designed by its own engineering staff.
Those familiar with electrotypes well know the superiority of the wet black leading process, especially for half-tones, stipple, Ben Day or fine type, where much of the detail and sharpness is lost in dry black leading, because of the crushing effect the brushes have on the wax mold. In this new type of black leading machine this fault is entirely eliminated, as the brushes never come in contact with the printing face of the mold; they merely polish the high built-up spots, thereby insuring better electrical conductivity to the wax, and a more uniform deposition of the copper shell.
Two of these especially designed machines are in constant operation in the ad department, which means the highest grade of advertising plates.
DEPOSITING THE SHELL
Those who are not technically familiar with electrochemistry are prone to think that the length of time a mold is kept in the electrolytic bath, i. e., the copper bath, determines the thickness of the shell deposited thereon. As a matter of fact, one electrotyper may keep his molds in the copper bath for three hours and get only as thick a shell as another who keeps his in but two hours. The element of time does not determine the thickness nor quality of the shell deposited.