Study of the influence of paper parameters on quality rizographic printing

Creation of new digital technologies let automate the reproduction of text and graphic information, led to the creation and development of the digital printing. Digital printing is a technology for producing prints in the printer based on the original layout, created as corresponding codes with a computer. One of the technologies of digital printing is a computer-to-press and one of the devices in this direction is risograph. The risograph printing quality is worse than offset printing. The text is printing with medium sharpness and images remind photos in old newspapers and require special preparation. But risograph is the most profitable solution for small and medium circulations from 50 up to 1000 sheets. Wide usage of risograph printing in typographies demands increase performance of the equipment with the high print quality of digital images. To improve the quality of risographic printing, the creation of methods is required to form the initial indicators of the original layout (clarity, correct transmission of halftones, contrast). At the same time, the result of obtaining high-quality images obtained by printing on a risograph is affected by surface microgeometry and the physical and mechanical properties of paper. So, the optical density of the ink layer on the print is largely determined by the structure of the sections of paper, in particular, absorbency and porosity. To obtain high-quality images on prints, it is necessary not only to customize the original layout, but also to select paper with such characteristics that would allow you to get the best result when printing on a risograph. Since the risograph occupies an intermediate place in quality between copying equipment and laser printing, a laser print is taken as the standard for print quality. And one of the tasks of the quality of risographic prints is to increase it to the quality of laser printing.