In today's packaging industry, the color contrast, brightness, and breadth of its printability of color inks are directly related to the quality of color prints, which places extremely high requirements on the ink blending method. Today, the editors of China Paper Net will discuss in detail the color printing ink deployment from the perspective of plate printing technology.

It is very important to mix inks, that is, to master the principle of using the same type of ink and auxiliary materials of the same type as much as possible. If the ink uses "05 type", the auxiliary materials should also match it to improve the printability of the ink. In addition, the number of primary color inks should be used as little as possible, that is, if you can mix two primary color inks, do not use the third one, so as not to reduce the brightness of the ink and affect the vividness of the color. There are two types of color ink blending. One is dark ink blending, that is, using three primary colors or secondary colors of the original ink without any diluting agent; the other is light ink, that is, adding diluting to the original ink The ink formulated by the agent.

(1) The mixing method and color principle of dark ink

Firstly, the color of the ink to be used should be judged initially based on the hue of the manuscript, and then an appropriate amount of each color ink should be placed on the ink console for a small amount of adjustment. When blending, one principle should be mastered, that is, gradually adding dark ink to light ink. Don’t take the dark ink first and then add the light color ink, because the light color ink has poor coloring power. If you use the method of adding light color ink to the dark ink to mix, it is not easy to adjust the hue, and the more the ink volume is, the more. Is undesirable. When the ink hue is adjusted to be similar to the original hue, you can use printing paper to scrape the ink color sample and compare it with the original. If there is color shift, add color correction until it conforms to the printed sample. After the ink hue is difficult to adjust, you can calculate their respective weights in order to adjust the batches in proportion. If you use three primary color inks to mix dark inks, you should master their changing law to improve the ink adjustment effect. For example: the three primary colors are mixed in equal amounts, and the resulting color is similar to black; the two primary colors in the three primary colors are equal or unequal in temperature adjustment, and various secondary colors can be obtained, and the hue is biased toward the color fruit with a large content ratio; The three primary color inks are mixed in various proportions to obtain a variety of complex colors; if black ink is added to any color ink, its brightness will inevitably decrease and the hue will become darker. If adding white ink, its brightness will increase. Intermediate colors and complex colors can be formulated with three primary color inks. However, considering the convenience of mixing and minimizing the number of inks used, intermediate color primary inks can be used.

When blending multi-color inks, you should grasp the color principle, and you must not try to adjust it by "adding points for this color, adding points for that color". For example, the blue in the pale lake green ink should be sky blue or peacock blue. Do not use dark blue to adjust it, because the dark blue ink has a red smell, and the color will be dark and not bright after being added. For the same reason, reddish dark yellow ink should not be used, but cyan light yellow ink should be used. For another example, when blending orange-red ink, rose red ink cannot be used because it has a blue taste, and the green composed of blue and yellow is the complementary color of red, which will make the ink lack bright.

The color of some inks has its own unique hue. Just as the hue of golden red is red with yellow light, the orange color will increase the vividness of black. If the orange color is printed, if the bright effect is not achieved with orange ink, and the printing is not realistic, the color of the printing is much better if the color is mixed with golden red and lemon yellow. Another example is to print the green landscape pictures in early spring, it is advisable to use light yellow ink to mix, can print the green and lovely leaves. If you use dark yellow ink, because dark yellow ink contains red flavor and red is the complementary color of green, the printed leaves must be scorched black, turbid, and do not reflect the breath of early spring.

When blending multi-color inks, if you use the complementary color law to correct the color cast, the toning effect will be better. If the purple odor of a certain complex ink is too heavy, yellow ink can be added to correct it; if the red odor is too heavy, green ink (such as peacock blue or sky blue ink) can be added to correct it, which can play a role in reducing the amount of increase and adjusting the hue. . If the black ink is yellowish and the blackness is not enough, you can add a small amount of emissive blue as a color-lifting material, because emissive blue is a blue ink with red light and is also the result of complementary colors.

(2) Blending of light-colored ink

The light color ink is the ink prepared by adding a diluent to the original ink, or the ink prepared by adding other color inks as the main white ink. The formulation method is based on the principle of diluting agent or white ink, supplemented by other color inks. First weigh the appropriate ratio of diluting agent or white ink, and then add the color ink in batches, so that the ink is stirred evenly and the hue change is observed. , When the degree of dilution is appropriate, use the printing paper to scrape the ink color sample to compare with the original, and adjust it until it is appropriate.

Diluted colors and inks can be distinguished from hue, and can also be divided into primary colors, secondary colors and complex colors. For those diluted with three primary color inks, just add the primary color ink in batches. However, if it is a secondary or multi-color ink and lacks ink adjustment experience, it is best to first adjust the original ink to a dark ink of the hue printed, and then add a thinner. It is an important technical link to deploy light-colored inks and master the degree of ink dilution. If the dilution ratio is not enough, the ink on the surface of the ink roller will be insufficient, the ink color of the printed product is prone to blurring, the ink layer is dry and not solid, and the color is not bright; if the ink dilution is too strong, only increasing the thickness of the ink layer can achieve the desired color In this way, the ink adjustment will easily make the low-key area of ​​the layout blurry, and it is difficult to distinguish the depth. At the same time, it is easy to cause the phenomenon of overprinting.

In the deployment of light-colored inks, suitable inks and thinners should be selected according to product quality requirements and paper characteristics. For example, if you use 10 type ink to print general products on offset paper, you can choose "915" thinner (weili oil) or "554" transparent oil. If you use 05-type ink to print fine products on coated paper, you should choose 05-90 bright paste or "8011, 8015" lightening agent. When preparing light-colored inks, attention should be paid to the original inks that are not resistant to light, oxidation, and easy to change color. Try to avoid using them to mix light-colored inks to avoid color instability. In addition, due to the high proportion of white ink, in addition to covering requirements and color matching needs, add a small amount for calling, and try not to use white ink to dilute. In order to prevent quality problems such as poor color overlap and color fading. When blending inks, you should also pay attention to the specific gravity of different inks. For example, if you use a lead chrome yellow ink with a large specific gravity and a peacock blue to mix green ink, after a long time, the small specific gravity ink will float up, otherwise it will sink. "Floating color", if you switch to yellow ink made of organic yellow pigments, the above phenomenon will not appear.

To sum up, only by learning and mastering color knowledge and understanding the relevant conditions and use characteristics of inks and auxiliary materials can we scientifically deploy various color inks to meet the requirements of improving printing quality and production efficiency.