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Views:7 Author:Site Editor Publish Time: 2019-12-01 Origin:Site
At present, many small and medium-sized printers use monochromatic offset presses to overprint color jobs. Simple prints are overprinted with two colors. Generally speaking, most of the four colors are overprinted on one side, but some printers have eight colors on the front and back. In this way, at the same time as the high quality and high precision of the printing machine is required, the printing operators must also have more exquisite skills.
So, how to arrange the printing color sequence in the overprinting process to be reasonable?
The reasonable arrangement of the printing order of the four-color machine is: black, blue, red, and yellow, and some are printed in reverse order of yellow, red, blue, and black. When printing on a four-color machine, the printing interval between colors is short, and the ink has no drying time, which is a wet-on-wet overprinting method. However, when printing on a single-color machine, the printing interval between colors is longer and the second When coloring, the first color is already dry, so it is a wet overprinting overprinting method. Because of the different overprinting methods, the color sequence arrangement is also different.
There are many types of color sequence arrangements for monochrome machines, but the specific choice of color sequence can be considered from the following aspects:
1. According to the lightness of the three primary colors, the color sequence must be printed first, dark color, and then bright color, that is, blue and black first, and red and yellow after.
2. Arrange the color sequence according to the transparency and hiding power of the three primary colors. Blue and black with poor transparency are printed first, and yellow and red with good transparency are printed after.
3. To arrange the color sequence according to the size of the graphic area, print the small graphic first, and then print the full version or large format graphic.
4. According to the characteristics of the original, color pictures with warm colors should be printed with blue or black first, and color pictures with cold colors should be printed with red or yellow first.
5. Consider overprinting, then print overprinting difficult colors first. In general, landscapes are printed in the order of blue and yellow, while person images are printed in the order of red and yellow.
Based on the above analysis, we recommend using a monochrome machine to print the four-color live color sequence: blue, red, yellow, and black. In this way, as long as the first two-color overprint is accurate and the color tone is good, the next two-color overprint will not be too obvious even if it is a bit inaccurate.
The operator should pay attention when changing the ink. In order to maintain the purity of the ink color, it is best to add a little ink of the next color to be printed when cleaning the natural color ink is about to be completed or when it is finished, and clean it again. Especially when changing dark ink to light ink, it is better to clean the machine twice.