The hue, brightness and printability of color printing inks are directly related to the quality of color prints, so it is necessary to correctly grasp the method of blending inks. From the point of view of the printing process of the printing plate, talk about the deployment of color printing ink.
It is very important to formulate inks to master the principle of using the same type of ink and auxiliary materials of the same type. If the ink is "05 type", the auxiliary material should also be matched to improve the printing suitability of the ink. In addition, the number of primary color inks should be used as little as possible. That is to say, if the two primary colors are used, the third one should not be used, so as not to reduce the brightness of the ink and affect the vividness of the color.
There are two kinds of color inks, one is dark ink, which is the original ink with three primary colors or intermediate colors, and the ink is not added with any thinner; the other is light ink, which is added to the original ink. The agent is formulated into an ink.
(-) Dark ink mixing method and color principle
Firstly, the ink color to be used should be judged according to the hue of the original, and then an appropriate amount of ink of each color should be taken and placed on the ink regulating table for a small amount of mixing. When arranging, you should master the principle that dark ink is gradually added to the light ink. Can not take the deep ink and then add the light ink, because the light color of the light ink is poor, if you use the method of adding light ink in the dark ink to adjust, it is not easy to adjust the hue, often the more the ink amount is adjusted, this It is not advisable. When the hue of the ink is adjusted to be similar to the hue of the original, the ink can be smeared with the printing paper, and then compared with the original. If there is color deviation, the color correction is performed until the printing sample is met. After the ink hue is difficult to adjust, the respective portions can be calculated to be batch-provisioned. If the three primary colors of ink are used to blend dark inks, they should be mastered to improve the ink adjustment effect.
For example, the three primary color inks are mixed in equal amounts, and the obtained color is approximately black; the two primary colors in the three primary color inks are equal or unequal in temperature, and various inter-colors can be obtained, and the hue is biased toward the color-fruit having a large content ratio; The three primary colors of ink are mixed in various proportions to obtain a variety of complex colors; black ink is added to any color ink, and its brightness is inevitably lowered to cause the color phase to become dark. If you add white ink, its brightness will increase. The intermediate color and the complex color can be formed by using three primary color inks, but from the convenience of blending and minimizing the number of inks used, the intermediate color ink can be used.
When formulating complex color inks, you should grasp the color principle, and you must not try to adjust the color by adding "this color plus dots". For example, the blue in the green ink of Tamsui should use sky blue or peacock blue. It should not be adjusted with dark blue. Because the dark blue ink has red flavor, it will inevitably make the color gray and not bright. For the same reason, you cannot add a reddish dark yellow ink. You should use a pale yellow ink. Another example is that when the orange-red ink is blended, the rose red ink cannot be used because it has a blue color, and the green color composed of blue and yellow is a red complementary color, which makes the ink color lack a vivid feeling.
Some inks have their own unique hue, just as the red hue is red and yellow, and the orange color will increase the blackness. Printing orange color, if you use orange ink to achieve less vivid effect, and the printing is not realistic, with gold red and lemon yellow mixed, printing color is much better. Another example is that the green landscape of the early spring should be printed with light yellow ink to print the green and lovely leaves. If you use dark yellow ink, because the dark yellow ink contains red, red is the green complementary color, the printed leaves must be dark, turbid, and can not reflect the breath of the early spring.
When blending complex inks, if you use the complementary color rule to correct the color shift, the color effect will be better. If the purple color in a certain color ink is heavy, it can be corrected by adding yellow ink; if the red color is heavy, it can be corrected by adding blue ink (such as peacock blue or sky blue ink), which can play a small amount and adjust the hue effect. . If the black ink is yellowish and the blackness is not enough, a small amount of blue light can be added as the coloring material, because the blue light is a blue ink with red light, which is also the result of complementary color.
(2) Dispensing of light-colored inks Light-colored inks are inks prepared by adding a thinner in the original ink, or inks mixed with other color inks by using white ink. The matching method is based on the principle of dilute agent or white ink, and other color inks are supplemented. First, weigh the appropriate ratio of dilute agent or white ink, then add the color ink in several steps, so as to mix the uniform ink and observe the hue change. When the degree of dilution is appropriate, use the printing paper to smear the color sample and compare it with the original. The diluted ink is distinguished from the hue, and there are also primary colors, intermediate colors, and complex colors. Anyone who uses the three primary colors to mix and dilute, as long as the primary color ink can be added in several stages. However, if it is color, complex color, lack of ink-adjusting experience, it is best to first blend the original ink into the dark color of the printed hue, then add the thinner. It is an important technical link to match the light color of the ink and master the dilution of the ink. If the dilution ratio is not enough, the ink volume on the surface of the ink roller will be insufficient, the ink color on the printed surface will be easy to bloom, the ink layer will be dry and not true, and the color will not be bright; if the ink is diluted too much, only the thickness of the ink layer can be increased to achieve the desired hue of printing. In this way, it is easy to make the paste in the low-key area of ​​the layout, and the depth is not clear. At the same time, it is easy to cause the bottoming phenomenon.
To match the light color ink, according to the product quality requirements, as well as the paper characteristics, select the appropriate ink and thinner. For example, printing offset paper with 10 type ink printing general products, you can use "915" dilute agent (Weili oil) or "554" transparent oil. If the printed coated paper adopts the 05 type ink printing fine product, it should use 05-90 bright light paste or "8011, 8015" extractant. It should also be noted that the original inks that are not resistant to light, oxidized, and easily discolored should be avoided for blending with light-colored inks to avoid color instability. In addition, because the white ink ratio is significant, in addition to the cover requirements and color matching needs, a small amount plus some for calling, try not to dilute the white ink. To prevent quality problems such as poor color stacking and color loss. When blending inks, you should also pay attention to the specific gravity of different inks. For example, lead chrome yellow ink and peacock blue with green ink are used. After a long time, the color ink with a small specific gravity will rise, otherwise it will sink, so it appears. "Floating color", if you use yellow ink made of organic yellow pigment to blend, you will not see the above phenomenon.
In summary, only by learning to master color knowledge and understanding the relevant conditions and usage characteristics of inks and auxiliary materials can various color inks be scientifically formulated to meet the requirements of improving printing quality and production efficiency.