The Influence of Plate and Blanket Cylinder Packing on Print Quality and Plate Wear in Sheet-Fed Lithographic Offset Machines

To guarantee image quality transfer in the lithographic offset printing process, there are some parameters that can be considered as direct influences, including dot gain, slurring, density, and plate wear. Today, there is a problem in many printing presses in Egypt that many operators modify packing based on their experience. This study was designed to assess the effect of different impression values between the blanket and plate cylinders by studying the impact of plate and blanket packing, including registration, density, dot gain, slurring, and plate wear. The study was divided into two experiments to evaluate how variations in plate and blanket packing thickness affect impression value, print quality, and plate wear. The results exhibit the relationship between the increasing plate and blanket packing and the quality of the output. Whereas, at 0.4 mm plate packing, plate wear began to appear. Moreover, when blanket packing was increased to 1.6 mm, the plate wore. In conclusion, the experimental study exhibited that the accurate plate and blanket packing might be calculated by these formulas. (1) Accurate plate packing = (undercut plate cylinder – plate thickness) + 0.1 mm. (2) Accurate blanket packing = (undercut blanket cylinder – plate thickness).