Reasonable arrangement of printing color sequence is of great significance

Multi-color overprinting, overprinting products, how to scientifically and reasonably arrange the printing color sequence, not only relates to the printing color quality, but also determines the product's effect. Therefore, according to the actual printing conditions and related factors, the scientific and rational arrangement of printing color sequence to achieve neutral gray balance, to improve the quality of product printing, is of great significance.

First, the rational arrangement of printing color sequence significance

Multi-color printing products, whether printed on a monochrome machine or multi-color machine to complete printing one or more times, must all be printed in a certain order, overprinting, overprinting, and the process of successive sets and overprinting. It is the ink overprinting sequence, usually called the printing color sequence. The practice of printing process shows that a reasonable arrangement of the printing color sequence is conducive to a better reproduction of the original color, and can correctly achieve the neutral gray balance of the printing. Neutral gray balance refers to under the certain printing conditions, yellow, magenta, and blue three-color version, from shallow to deep according to a certain dot area ratio combination overprint, in the embossed with different brightness of the achromatic. Neutral gray balance is a ruler for controlling the quality of printed matter in the process of lithographic printing, and expresses the degree of color reproduction of each level of printed copy from light to dark. If the printed part is slightly colored with neutral gray, the printed color can be more easily identified. Therefore, to achieve a neutral gray balance is the basic condition for the color prints to maintain clear image outlines, rich layers, and soft colors. Scientifically and reasonably arranging the print sequence is an effective measure to achieve neutral gray balance and improve product quality.

Second, according to the characteristics of the substrate to consider printing color order

We know that due to the different types of substrates, their respective characteristics are also different. For color printing, such as coated paper, offset paper, whiteboard paper, glass paperboard, and aluminum-plated paper, the printability is different due to different materials and production processes. Such as when the material surface strength, gloss, ink absorption, moisture content and pH, there are differences, in order to prevent off powder, pull hair, sticky dirty, overprinting and drying bad and other ills, to bring obstacles to the normal printing, so The arrangement of the color sequence should be considered from the paper characteristics. For paper with good paper gloss and high tightness, for example, dark color should be printed first, and light color should be printed afterwards. On the contrary, if the texture of the paper surface is rough and loose, the dark color should be printed first. Papers with poor dimensional stability should be considered from the point of view of registering. Firstly, there should be no color plate with precise overprinting of the printing plate surface, so that the printing plate can be adapted to the environment, and after the moisture content of the paper is relatively balanced and stable, the printing is overprinted in sequence. High-precision color version.

Third, according to the differences in the structure of the printing machine to consider the arrangement of color order

Because the type of offset press is different, there are certain differences in the overprinting method and effect. We know that monochromatic machines are "wet-pressed" sleeves and overprints, while multicolored machines are combinations of "wet-wet-wet" and "wet-pressed-dry" sleeves. Overlays and overprints are also effective. not exactly. The color sequence of a monochrome machine is generally: yellow is printed first, followed by magenta, cyan, and black editions. This kind of color sequence can make yellow play a role in supporting some products with poor paper quality and achieve the purpose of improving the printing color effect. For printing fine products, due to the better paper quality, the color sequence can be printed from dark to bright, such as from black → blue → magenta → yellow or black → yellow → magenta → blue Print. Two-color printing machine before the two-color printing is a "wet-pressing wet" printing form, printing the third color is a "wet-pressed dry" printing form, so its color sequence arrangement is more difficult than the monochrome machine, the factors involved are more . The printing sequence of a general two-color machine includes: black → yellow → magenta → blue; blue → yellow → black → magenta; blue → magenta → black → yellow or black → blue → magenta → yellow, among which magenta Cyan can change the color sequence according to the actual situation, as shown in the text area can be placed behind the printing. The four-color printing machine is a “wet-pressing wet” printing form. In addition to the first color, the other three colors are completed under the “wet and wet” condition. The printing color effect can be revealed immediately after the overprinting, which is beneficial to timely Correct color cast. Usually the color sequence of the four-color machine is: black → blue → magenta → yellow or black → magenta → cyan → yellow. The arrangement of the color sequence should not only consider the characteristics of the manuscript, but also consider the structure, performance, and registration of the machine, so as to achieve a process effect of vivid color printing and accurate overprinting.

Fourth, according to the different layout of the layout of the printing plate layout

Overprinting of the product's layout has both dot and field sections. To make this kind of product dot printing clear, the ink on the ground is thick and colorful, and it is conducive to the accuracy of overprinting. It is usually necessary to print an anilox version first and then print it on the ground. Edition; from the perspective of preventing the ink from being scratched and stained, it is advisable to print a small area of ​​ink on the layout first, and a large amount of ink on the layout to be printed on the back. The practice of the process clearly shows that a large area of ​​the layout is printed on the back, which not only improves product registration, but also improves labor efficiency. This is because, if a large-area layout is printed beforehand, the printed sheets are prone to curling, elongation, and other undesirable phenomena after absorbing ink. Once the printed sheet is curled, it will affect the normal feeding and positioning. In this way, when the second set and the overprinting, it is often necessary to knock the sheet on the paper to increase the stiffness and flatness, and then to achieve a smooth loss. Paper and positioning. This type of printing sequence has a low accuracy of overprinting, and when it is knocked on paper, it is laborious and laborious. The author has seen such a situation: There is a packaging printing company printing trademark products in the past, has been accustomed to use the first printing large layout, after printing small layout of the "format" process operating procedures, the results of the deformation of the print Zhang powerful, some parts of the Layout profile overprinting errors of up to 0.5~1mm are not allowed, and the amount of scrap is very alarming. Later, the printing color sequence was changed to a small printing area first, followed by a large printing area; the printing area with a lower printing accuracy was printed first, then the high precision printing area was overprinted, and the overprint quality of the product was greatly improved. The consumption has dropped significantly. Therefore, when overlapping colors, as long as the color effect is not affected by the ink (such as stacked ink does not add white ink), should try to arrange to print small layout, after printing large layout.

Fifth, according to the original color characteristics to consider the arrangement of color order

We know that the larger the ink-receiving area on a printed product, the more unfavorable it is for overprinting. The overprinted ink is always brighter than the pre-printed color. Based on this feature, whether it is three primary colors ink or spot color ink; whether it is an anilox version or a field version, it is preferable to first print a color plate with a small area, and then print the color version of the ink area (gold, silver, and white ink). There are exceptions to the overprinting of other colors on the color plate, which not only facilitates smooth overprinting, but also improves the overprint accuracy of the product, and can highlight the main screen. For example, for beer box paper printed with a landscape image as the main theme, blue and yellow are the main colors, the dot area is relatively large, and its ink receiving capacity is also large, while black and magenta versions have a smaller area. Printed first, then printed in blue and yellow, so that white paper can also reduce the drawbacks of falling powder, pulling hair, improve the quality of carton printing. The warm-colored manuscripts with characters as the main picture should be printed in green and black, and then printed yellow and magenta.