XM (Cross Modulated) Screening Technology

Increasing Print Quality in a CtP Workflow

Introduction

Eliminating film in the plate-making process has done more than shorten the workflow. Removing the intermediary image transfer has eliminated prepress registration errors and shortened press make-ready. These on-press improvements provided immediate benefits for the printer. Now that CtP technology has been widely implemented, customers are demanding higher print quality as well. CtP enables the use of higher screen rulings – a practical method to deliver the quality that customers now demand.

Computer-to-Plate, the Enabling Technology

Computer-to-plate technology has brought with it a number of benefits. By eliminating the film intermediary and imaging digital data directly to plate, registration is exact. Make ready is reduced by as much as 50%. The ability to more precisely control the halftone dot has opened the door to new methods of achieving higher quality. The production benefits afforded by CtP have also driven printing companies to seek a new competitive edge. In the attempt to achieve higher quality, they are printing at high screen resolutions of 175 and 200 lpi (lines per inch). Others have revisited FM screening technology which had been cast aside because of the difficulty holding the smallest microdots from the film to plate transfer. Yet, printing with conventional screens at high line rulings or controlling a 10-micron FM dot still requires a number of workarounds, leaving the user's desire for higher quality with ease of use unrequited. To understand the characteristics needed in a new screening technology, it is important to look at the benefits and advantages of various screening methods...