Making negatives and plates for printing by electroerosion. Introduction and overview

The most familiar electroerosion printers operate by removing the whitish or silvery aluminum overlayer from discrete areas of a special paper so as to reveal a black underlayer. The direct negative/direct plate (DNP) material described here is a new dual-function printing material which, when employed together with an electroerosion printer, allows direct generation of negatives or (short-run) offset printing plates suitable for use in printing and publishing applications. The DNP material has been specifically developed for use with the IBM 4250 electroerosion printer family, allowing these printers to generate negatives, plates, and camera-ready copy directly from the computer with no chemical processing.