A Contribution to the AM and the FM Screening in the Graphic Reproduction Process

Developing and reproduction through the Computer to Plate (CtP) systems bring out a number of novelties, even in the field of different screening methods. The conventional screens (amplitude modulated screening method - AM) are still being used due to their predictability which comes as a result of their longer usage in the printing process. In certain types of reproduction the usage of frequently modulated screening method (FM) is becoming wider. In this paper the original was reproduced by using the AM and the FM screening method in the same CtP workflow, after which it was printed in offset. The differences in the quality of prints have been defined by measuring the mechanical and the optical characteristics of the screening elements. The results of the instrumental measuring have been confirmed by visual assessment. Different models and conditions of the usage of certain types of screening elements for characteristic motives reproduction have been suggested. This kind of investigation will simplify the process of deciding which screening element will find use in the graphic reproduction. The proposed new screening method will correct the disadvantages of the investigated screens.