How to achieve colorful effects in color printing

Color printing should comply with the basic requirements of the original manuscript. In addition to ancient painting reproduction or other special requirements of the arts and crafts, securities, etc., under normal circumstances there are colorful color print quality requirements, how to print from the color process And raw materials used to achieve this quality requirements? The author believes that the following conditions must be grasped in order to obtain the vivid effects of printing.

First, the whiteness and absorption of paper

Whether or not paper is white is the basis for printing colorful or not. Purely white paper, can reflect nearly all the color light. Conversely, gray and black paper will absorb some of the light, causing the hue, lightness, and purity of the print to be lost. From the color analysis, on the printed paper, in addition to the visual color created by the space blending of the color dots by the additive method, the color of the surface of the paper without the printed dot (or pattern) is actually involved. This space mixes. The gray paper is like adding a small amount of ink to the various inks, so the high-purity color ink is not visually visible, and the dark color is displayed. Practice has proved that if other conditions are exactly the same, the vividness of the pictures printed on papers with different degrees of whiteness is completely different. Only from the comparison of color brightness analysis. If only black text and white paper are printed, because of black and white contrast, the black characters are darker and the white paper is more white, creating a sharp contrast. It can be inferred that: as the basis of printing, the whiteness of paper is directly related to the vividness of the print. Similarly, the reddish color of the paper tends to make the prints more red and greenish so that the prints tend to be blue, which needs to be taken into account when using them. In addition, the absorption of paper has a great influence on the color. Absorptive paper will cause the pigment to infiltrate into the paper together with the binder. The blot cannot form a sufficiently full ink layer on the surface of the paper, causing the color saturation to be lost and the color to be difficult to be bright.

Second, the deployment of color ink and how to ensure the color in the rolling, coating

From the purity of the three elements of color, it can be known that the saturation of color refers to the pure degree of color. To make colorful, we must pay attention to the choice of color ink, in addition to the standard Sanyuan ink more pure hue, there are many original ink is the three primary colors, their hue and manuscript in line with the use of increased brightness of the imprint. To make the transferred ink colorful, special attention should be paid to avoiding complementary colors. For example, in the lush green forest of early spring, yellowish leaves can make the printed leaves green and lovely. If dark yellow ink is used, yellow ink contains red taste, and red and green are complementary colors. The printed leaves are dark and turbid, reflecting the breath of early spring. Not to mention bright. Pay attention to the cleaning of the ink tank and the ink roller during printing. This means that when changing the ink, it is necessary to prevent the color cast caused by the ink in the ink tank, the ink roller, and the water remaining in the previous ink color, especially when the dark color is changed to a light color, and when the black and blue printing is yellow, if not Pay attention to the cleaning work will cause color cast, this will also affect the print of the colorful degree.

Third, the complete copy of outlets

When the dots are enlarged, the ones that have been enlarged will have to reduce the thickness of the ink layer. This will make the low-tone and solid parts not thick, and the color saturation will be weakened, and the inherent hue characteristics of this color cannot be exerted. The printed clothes are old, and the Indian landscape is cloudy.

Fourth, ink coloring and emulsification, dilute the impact

In addition to the special circumstances in which the color needs to be diluted, the tinting power of the color ink is low, and the auxiliary material is not properly added during the printing process to dilute the ink color, or auxiliary materials for suppressing drying are added, and the ink emulsification is large. These factors may make printing inks and saturation less. Slow drying after printing on paper, strong permeability, long penetration time, so that the imprinted ink layer is not thick, resulting in the color of the imprint is not very bright.

Fifth, ink layer thickness

Whether imprinted ink layer thickness is just full, as is whether this is in line with the color, whether bright is the key factor, which is particularly important at the time of going to press the issue of the kind. How much the thickness of each ink layer, if it deviates from the original, will inevitably distort the hue of the overlayed picture. It is very important to control the amount of ink of the first color of the basic color. If the foundation is not played well, it will be difficult to remedy it in the future. In order to make the hue closer to the original, the amount of the basic color ink is less, and the various colors must be With the decrease, the resulting picture has less ink in each color, and there is no color at all. On the contrary, the basic ink layer is printed too thick, and afterwards, the colors must only be thicker. If it is not thick, the hue will lose its balance. The hue of the print is close to the original, but because the ink layers are thick, the hue is low, and the hue is flat, the printed image is dull and dark. The level is unclear and there is no such thing as a colorful effect. Under normal circumstances, in order to achieve the colorful effect of the picture, the amount of ink must be printed. Only in this way, other color ink layers can be printed full, or the ink color is too dark and too light to be remedied, especially after the printing is dark. remedy. For example, if the yellow ink is excessive, it will inevitably cause the proportion of the picture color to lose balance, so that the amount of magenta and cyan ink will also increase accordingly. Although the hue is close, but the network is also ambiguous, the quality of the printed product is reduced. (Author: Wang Nengyou)