The correct transfer of dots at the time of printing is one of the key elements for evaluating the quality of printing. However, the concept of controlling percentages and tonalities in traditional screen printing is no longer applicable. FM network printing can only inspect whether the dots are complete and not lost. The increase in outlets is unavoidable. We know that if the pressure is too high in the printing, or if the amount of grinding is too large, the idea will definitely increase. If you press the theoretical rule of the perimeter of the network, the dot gain is calculated by the perimeter of all printing dots, then because the dot is small and almost isolated, the sum of the dots around the dot is much larger than the traditional dot, but all dots are normal. The increase in the situation is even. At the same time, there is almost no limitation on the high-accuracy recording of the FM network, the fineness of the dots, and the reproducible tone. Therefore, the image is still soft and clear, but it does not mean that the pressure or ink can be increased. Because the FM network is isolated and unevenly distributed, the force on each part of the unit area is also uneven. In particular, the highlights are few and dilute, the stress on the unit area is the largest, the wear is severe, and the risk of network loss is greatest. . Therefore, the use of rigid pads is more suitable for the printing of FM networks.
In addition, because the entire circumference of the inked dot on the print is surrounded by the wetting liquid, it is prone to be wetted by the liquid, and excessive water consumption or inappropriate pH may cause dot loss. Therefore, the key to printing is to master the printing pressure and ink balance. At the same time, the print quality control strips used in the original printing are not suitable for FM network printing. It is necessary to develop new tools for measuring and controlling the printing quality. To sum up, the printing of FM network points throughout the printing process must be standardized in all aspects, and the environmental conditions are extremely demanding, especially at the plate making stage. However, in the printing operation, it is obviously easier than traditional dot printing.
a. Insensitive to overprinting accuracy requirements. Because the frequency modulation points on each color version are irregularly distributed, even if the distribution of dots of different colors in the same site is different, slight errors do not reflect major changes in color, and the gray balance is easily obtained, so it is possible to save costs due to adjustment of overlay errors. A lot of time.
b. The key to printing is to pay attention to the fact that FM outlets cannot be lost. Even if the outlets are increased, they are uniform and will not affect the change of the adjustment. At the same time do not have to worry about will produce white spots, moire and other phenomena.
c. Because the FM network is fine, dark tone is not easy to produce paste, so the ink balance is not very sensitive.
d, because the FM network is randomly distributed, and was isolated, the printing is not easy to cause the paper to pull hair, the phenomenon of increase in the back side is also greatly reduced, so the viscosity of the printing ink can be slightly larger.
According to the experiment, the use of a 1200 dpi laser spot as an ink point for the FM network printing not only can improve the printing quality, but also can reduce the labor level of the operators. It is a new technology worthy of promotion.