On Several Factors Influencing Overlay Accuracy

Color printing is the process of color combination. This process is called overprinting. Accurate and intuitive overprinting is to make bulk prints a copy of the original. However, in the production process, overprint errors often occur, affecting the appearance, or even become a waste product. There are many factors that affect the accuracy of overprinting. Let's choose three of them:

1. The influence of printing plates on overlay accuracy. Lithographic printing plates are mostly thin and light aluminum materials. During the printing process, the accuracy of printing may be affected by changes in its shape or volume. The deformation of the printing plate is generally caused by two aspects: one is stretching deformation, and the other is baking deformation.

2. The impact of paper on the accuracy of printing, the composition of the paper is mainly fiber. The characteristics of fibers are water swelling and syneresis. In the offset printing process, when the first color is printed on the second color, the print inaccuracy caused by the expansion and contraction of the paper is very obvious. Paper structure has high strength, good smoothness, thick coating, and low water absorption. It is particularly serious for some papers with loose structure, light sizing and strong water absorption.

3, mechanical influence on India, printed paper on the machine must be the effective control of the mechanical parts from start to finish, the relative position in the transfer process must be stable. Otherwise it will affect the printing effect. In addition, when the paper is peeled from the drum, it is subjected to adhesion force and peeling tension. If the gripper teeth cannot overcome the peeling force, small movements will occur. This kind of monochromatic machine now appears to be overprinted and appears as a ghost image on a multicolor machine.

Source: long time candor