Vols. 3-13, 1961-71 one issue each year includes a directory issue: Purchasing directory.A new software program, called Gerber Graphics Generator (3G), developed by Applied Programming Technology, a subsidiary ... The material was designed to produce good quality halftones without the use of film negatives. ... over after the projectionist has focused the first slide of a presentation using the Kodak Ektagraphic slide projector, model AF. ... Orientation diagrams aid in positioning the guide.