The purpose of this research was to investigate the effects of dry etching techniques on changing halftone dotsizes. Dry etching, or photographic color correction, has emerged in recent years as an alternative to traditional dot etching for making local corrections to color separation halftones. This study examines six factors related to dry etching. First, three types of original halftone dots were considered: laser formed (hard) dots from a Hell DC-300B scanner, laser formed (semi-hard) dots from a P.D.I, scanner, and contact screen (soft) dots from a Crosfield 510 Magnascan scanner. Second, the original dot-sizes being treated were fixed as close as possible to five target dot-sizes (5,25, 50,75, and 95$). Third, three types of dry etching treat ments were applied a technique of overexposure; the use of a 4-mil clear spacer film; and a technique of exposing through the base. Fourth, sixteen levels of corrective treatment were applied ranging from 1 times dot-for-dot exposure to 100 times. Fifth, two types of graphic arts films were test ed lith film and rapid access. Sixth, two generations of contact printing were compared original positive-to-inter mediate negative and intermediate negative-to-duplicate positive
