Studying the effect of the quality of duplex paper on the quality of printed packages

Treating prints with ultraviolet rays is one of the best finishing methods in the printing industry to protect the ink layers and enhance the physical and optical properties of the print, and it also gives a bright and vibrant appearance to the print.

The problem was that the print appeared dark after the printing and finishing operations were carried out - which led to the customer refusing to receive the production. The aim of this study was to determine the reasons that led to the change in color of the printed product after it was printed and treated with varnish. The importance of the research was to reach the physical and optical properties of 250-gram cardboard (Duplex - Egyptian), which positively affect the quality of the printed product,. It is printed using the Litho offset, and the quality of the prints is measured using a control tape printed on sheets of duplex paper, and the results are evaluated according to quality standards, but the lack of paper quality and the difference in weights of some papers led to the emergence of many problems in the finishing stage. The results of the research were that printed quality is clearly affected by paper manufacturing, and that optical properties have a significant impact on quality . The whiteness of the paper has a positive relationship with obtaining the desired glossiness of the printed matter. When the varnish treated with ultraviolet rays was added to the printed matter, the print turned into a dark color. The solution by the printing press was to apply a water-based varnish after completing the printing process and before the varnish treated with ultraviolet rays. To obtain a product that matches the required production specifications. The results of the research were that when the varnish treated with ultraviolet rays was added to the print, the print turned into a dark color - and the solution by the printing press was to apply a water-based varnish after completing the printing process and before the varnish treated with ultraviolet rays in order to obtain a product that conforms to the required production specifications. The research recommendations were that if the same problem that is the subject of the research appears in any printing press and under the same constants, the printed matter should be treated with water-based varnish first, then treated with a varnish that dries with a LED UV.