How to achieve the effect of bright colors in the

How to achieve the effect of bright colors in color printing

when color printing, the color should meet the basic requirements of the original. In addition to the reproduction of ancient paintings or other graphic arts and crafts with special requirements, securities, etc., in general, color printing also has the quality requirements of bright colors. How to achieve this quality requirement from the selection of color printing technology and raw materials? The author believes that we must grasp the following conditions in order to achieve the effect of bright printing colors

I. whiteness and absorption of paper

whether the paper is white or not is the basis of bright colors in printing. Completely pure white paper can reflect nearly all the colored light. On the contrary, grey and black paper will absorb part of the color light, so that the hue, brightness and purity of the imprint will be lost. From the analysis of color degree, on the paper printed with pictures, except for the visual color formed by the spatial mixing of various color points through the additive method, the color of the surface of the paper without printing points (or patterns) is actually involved in this spatial mixing. Gray paper is like adding a small amount of ink to all kinds of inks, so you can't see the color ink with high purity visually, and it shows a dark color. Practice has proved that if other conditions are exactly the same, the brightness of pictures printed on paper with different whiteness is completely different. Only from the contrast of color brightness. If you only print black words and flawless white paper, because of the contrast between black and white, black words are darker and white paper is whiter, forming a sharp contrast. It can be inferred that as the basis of printing, the degree of new materials such as white paper, coffee bean fiber, pearl protein fiber, wood fiber and so on is directly related to the bright color of imprinting. Similarly, the paper with reddish color makes the impression tend to be red, and the paper with bluish color makes the impression tend to be green, which should be considered when using color. In addition, the absorption of paper has a great influence on color. The paper with strong absorption will make the pigment penetrate into the paper together with the connecting material. The imprint cannot form a sufficient full ink layer on the paper, which will cause the loss of color saturation and make the color difficult to be bright

second, the allocation of color ink and how to ensure bright colors in rolling and coating

from the purity of the three elements of color, the saturation of color refers to the purity of color. To make the color bright, we should pay attention to the selection of color ink. In addition to the standard three original ink color phase is relatively pure, there are many original inks that are interchromatic of the three original colors, and their color phase is consistent with the original to increase the bright degree of imprinting. To make the adjusted ink colorful, special attention should be paid to avoiding complementary colors. For example, printing lush trees in early spring, using light yellow can make the printed leaves green and lovely; If you use dark yellow ink, yellow ink contains red flavor, red is the complementary color of green, and the printed leaves are scorched and turbid, which can not reflect the breath of early spring, let alone bright. Pay attention to the cleaning of ink tank and ink roller during printing. That is to say, when changing the ink, it is necessary to prevent the color deviation caused by the ink tank, ink roller and water stained with the ink of the previous print color, especially when changing the dark color to light color, and changing the black and blue color to print yellow, if you do not pay attention to the cleaning work, it will cause color deviation, which will also affect the brightness of the printed matter

III. complete reproduction of dots

when dots are expanded, the same color from which 175 kinds of pests are intercepted has to be expanded, and the ink layer thickness has to be reduced, which makes the low tone and field part not thick, and the color saturation is weakened, so the inherent hue characteristics of this color cannot be played. When printing clothes, the clothes look old, and when printing scenery, it seems to be a rainy day

fourth, the coloring power and emulsification of ink, the impact of dilution

except for the special cases where the color needs to be diluted, the coloring power of color ink is low. In the printing process, the auxiliary materials are improperly added, which can not meet the quality requirements of the market and dilute the ink, or the auxiliary materials that inhibit drying are added, and the ink emulsification is large. These factors may reduce the printing ink and saturation. After printing on the paper, the drying is slow, the permeability is strong, and the penetration time is long, which makes the imprinting ink layer not thick, resulting in the imprinting color is not very bright

v. thickness of the imprinted ink layer

whether the thickness of the imprinted ink layer is just full is the key factor for whether the color conforms to the original and whether it is bright, which is particularly important when issuing the printed samples. The thickness of each color ink layer, if it deviates from the original, will inevitably distort the hue of the superimposed picture. It is very important to control the ink volume of the first color of the basic color. If this foundation is not well laid, it will be difficult to remedy the various colors in the future. In order to make the colors close to the original, the ink volume of the basic color is reduced, and the various colors must be reduced in the future. In this way, the ink layers of the obtained pictures are less, and there is no bright color at all. On the contrary, if the ink layer of the basic color is printed too thick, the colors will have to be thicker in the future. If not, the hue will lose balance. Although the printing color is close to the original, the printed pictures are dull and dense due to the thick ink layer of various colors, the paste in low tone and the flat in high tone. The level is not clear, nor can it be said that the effect of bright colors. In general, in order to achieve the effect of bright colors in the picture, the ink volume should be printed enough. Only in this way, the ink layer of other color plates can be printed full. Otherwise, the ink color is too deep and too light, which cannot be remedied, especially after printing deep, it is more difficult to remedy. For example, excessive yellow ink will inevitably cause the color proportion of the picture to lose balance, and the amount of magenta and cyan ink will also increase accordingly. Although the hue is close to covestro: the high-performance plastic solution for battery shell is close, but it is dot and paste, resulting in the decline of print quality. (author: Wang Nengyou)