What does overprinting mean? Overprinting refers to the requirement of overlapping and aligning the patterns of various color plates during multi-color printing. But when we operate the overlay printing, we often encounter situations where the various color patterns overlap but are not aligned during printing.

So what are the reasons for the failure of overprinting, mainly including the following points:

Too many rubber blanket pads, insufficient rubber blanket pads, loose rubber blanket, rubber blanket detachment, inconsistent rubber wiring speed, excessive water absorption of paper

Having been engaged in offset printing for so many years, you must have encountered regular short cracks at the joint between the rubber blanket and aluminum plate, and even these small cracks are perfectly transferred to the finished product you want to print. Does this make you instantly doubt the quality of the rubber blanket used? Did I buy a fake or defective product. But the actual situation is not like that. Below, the editor will tell you the real reason for this phenomenon.

There are two main reasons for your reference: 1. In the process of using rubber blanket printing, if the residual ink in the card slot is not thoroughly cleaned after each use, over time, these inks will become very hard after drying and oxidation. In this case, once the rubber roller starts running, it will cut the surface of the rubber blanket in contact, which can easily lead to the formation of small cracks.

2. Additionally, you need to check if there are cracks or uneven cuts on the PS or CTP board. If so, these uneven surfaces can increase the friction between the machine and the rubber blanket printing surface during operation, leading to the formation of small cracks.