Non Periodic (Stochastic) Screening, Offset Negative and Positive Tone Reporduction, Part 1

It was found that the tone reproduction output of positive and negative non periodic (Stochastic) output differ from one another in the plate exposure and ink on paper printing steps of the offset reproduction train. It was confirmed that the output of negative acting films exhibit extensive dot (spot) gain. Where the image acceptance criteria match the period screen image then file compensation is required. In comparison, positive files need comparatively little compensation. The positive output dot (spot) size can be reduced during plate platemaking (exposure). It was confirmed that the output of negative acting films exhibit extensive dot (spot) gain. Where the image acceptance criteria match the period screen image then file compensation is required. In comparison, positive files need comparatively little compensation. The positive output dot (spot) size can be reduced during plate platemaking (exposure). More work is needed to isolate platemaking (exposure) gain effects from those produced in press, ink on paper and printing.