Abstract:

　Introduction of tower type offset press, which can perform 4-colors printing on both sides, proceeds in newspaper printing caused by the trend of multi-color demand. However, 'out of register' in color printing at pasting paper rolls frequently occurs in tower press compared with satellite type offset press.
　Paper deformation to parallelogram, which causes leaning stack of non-impact printer paper, also relates to the runnability of news printing paper in tower press. It is observed that the pass line of paper web in tower press changes according to the direction of paper deformation to parallelogram. The degree in 'out of register' becomes greater when the paper rolls which have different directions of paper deformation to parallelogram are pasted each other.