How to adjust the color of printing ink?

During the printing process, many sample colors are not directly usable without the ink from the county, and the production enterprise needs to mix them according to the sample colors. This process is called ink color matching, while the printing factory is called ink blending. The color matching of printing ink is very important and also a difficult problem for printing.

Usually, using different proportions of three primary ink colors to blend any specific color follows the theory of three primary colors and has certain rules. The ideal three primary colors have the same coloring power, and can be called black after equal mixing. In fact, the three primary colors have optical defects that cannot be overcome, resulting in a brown color band. Ink can be mixed in different proportions to obtain different color schemes, which tend to be mixed with one or two primary ink colors with larger proportions. After equal mixing of two primary ink colors, a standard intermediate color phase can be obtained; Two types of primary ink are mixed in different proportions, resulting in a color transition that leans towards a larger amount of primary ink.

Printing ink color matching techniques:

1. Principles of color matching

(1) The color matching of printing ink should be as much as possible using the same model of ink produced by the ink factory, and the color saturation (chromaticity) of the setting ink should be higher than that of the color saturation formed by mixing two types of ink.

(2) If you want to use several color schemes of ink for color matching, you should try to use finalized ink with similar colors to mix new color schemes of ink.

(3) When color matching, the variety of ink should be minimized as much as possible, because the more types of ink used for color matching, the higher the extinction ratio, which will reduce the brightness and saturation (chromaticity) of the color matching ink. Therefore, it is possible to use one color tone instead of two color inks.

(4) When blending light colored ink, white ink should be the main ingredient, and a small amount of primary color ink should be added.

(5) When printing plastic packaging materials, in order to obtain a light colored ink and still maintain the required viscosity of the ink, a diluent should be used, and diluents should be avoided as much as possible because plastic is not easy to absorb solvents, there is too much diluent, drying energy needs to be increased, and the bonding force decreases due to the low solid content.

(6) The inks of different manufacturers, models and varieties cannot be mixed, otherwise the gloss and fastness of printing after mixing will be affected, and even the ink gel may be caused.

2. Properly utilize complementary color relationships

According to the principle of complementary colors in the color subtractive method, complementary colors are added to eliminate color. When blending color ink, it is important to use complementary colors correctly. Sometimes complementary colors should be avoided, for example, when mixing intermediate ink or diluting primary ink, it is advisable to avoid the mixing of complementary ink as much as possible, because the more complementary colors are mixed, the more components of the fading component in the ink, the lower the saturation of the color, and the darker the color. For example, if there is color deviation when mixing ink colors, the principle of complementary colors using subtraction can be used for color correction. If the ink color is slightly yellow, in order to eliminate yellow, a small amount of purple blue ink can be added to the ink, because yellow and purple blue are complementary colors, and the two colors mix to form a dull color.

If the color phase needs to be adjusted during ink adjustment, complementary colors can also be used to solve the problem. For example, when the blue ink turns red and needs to be changed to a yellow tone, a small amount of green ink should be added to the ink, because the red and green light reflected by the ink mix to form a yellow light. Similarly, if the blue ink tends to turn yellow and needs to be adjusted to turn red, a small amount of blue-purple ink should be added. The purple blue ink reflects red and blue light, while the yellow ink reflects red and green light. When the two ink colors are mixed, except for fading, the overall color of the blue ink tends to turn red.

In daily life, in order to make white more white, just add a small amount (1%) of ultramarine to the white to eliminate the yellow tone in the white. When the black ink is not black enough, simply add a small amount of luminescent blue ink to the black ink, and the black ink can turn into black. In printing, adding a small amount of phthalein blue to black ink can eliminate the yellow tone in black ink, making it even darker.

Printing ink color matching requirements:

The actual color matching techniques are mostly dominated by experience and intuition. However, there are many types of ink, and the treatment and use of new types of films and printed materials are diverse. Therefore, color matching technology must take into account a very wide range while depending on proficiency.

Strictly speaking, the progress of color matching technology varies from person to person, but different color matching techniques and basic principles, despite efforts, are in vain. Therefore, regardless of difficulties or troubles, the first thing to do is to rely on basic color matching to accumulate original experience, and then add intuition to achieve as ideal a result as possible. In order to improve the accuracy of color matching, there are the following requirements for color matching personnel and color matching environment during color matching:

Color matching personnel requirements: Color matching may seem simple, but in reality, it is not. Not only is color matching experience, but even advanced computer color matching ultimately relies on human vision for judgment. To evaluate the correctness of colors under certain conditions and standards, color matching personnel need to possess knowledge of color mixing, basic color theory, and various related knowledge, as well as practical ability. Color matching personnel should have a keen ability to distinguish subtle changes in colors and be able to have this ability at different times and places. From a physiological perspective, color matching personnel should be aged 20-30, healthy and not easily fatigued.

Color matching environment: A simple and commonly used method for color comparison is to use bright indirect sunlight, with snow-white walls, and a bright room with windows facing north is the most ideal. If color matching is done under indoor artificial lighting, a calibration light source should be set up, with a color temperature of 5000 ± 200K, suitable for observing color photography films. When strict color matching is required, it is best to compare and verify the color matching under these two lighting conditions.