Factors related to the quality evaluation of the h

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Factors related to the evaluation of print quality

China's tinplate printing industry has learned that the factors that may affect the quality of print can be summarized into three main categories

first, aesthetic factors

because printed matter is a visual product in the final analysis, when people evaluate the quality of printed matter, the first feeling is the aesthetic effect of printed matter

the aesthetic effect of printed matter is mainly related to the design level of craftsmen. The font selection, color design, art pattern, image position, layout style and the selection of paper and ink in the design are all related to the aesthetic effect of the printed matter. The power supply must have a good "grounding" device. Good design can make printed matter show good aesthetic characteristics, but it is difficult to describe the good degree of design with quantity. Sometimes, "good" design does not conform to the laws of typesetting, color combination, image synthesis and so on. Some people think that a bad design may be appropriate for the cover of some commemorative books, but it is not appropriate for advertisements of high-grade cosmetics. In addition, most of the designs of previous years are outdated by current standards. That is to say, in terms of image design, there is a question of whether it is "fashionable". It can be seen that the aesthetic factor of print quality is actually the embodiment of the imagination and creativity of designers. An excellent designer should be familiar with the aesthetic design criteria, and should know the technical constraints of printing materials, inks and printing processes, so as to produce excellent aesthetic effects on printed materials

second, technical factors

after completing the format design of the original print and determining the printing method, ink and substrate materials, it is technical factors that can affect the printing quality. Technical factors are the factors that affect the quality of printed matter in each process of printing production, and reproduce the designed content as faithfully as possible within the limits of the characteristics of plate making, printing equipment and printing materials

the technical characteristics of print quality include image clarity, color and gradation reproduction, gloss and texture. Some of these characteristic factors can be expressed quantitatively, such as color and coordination. People can control these factors in each process of the replication process; There are some technical factors that cannot be expressed quantitatively, but can be described in language. For example, in order to obtain the best print quality, we must minimize the possibility of moire, which is the form of language description; Another example is that the gloss characteristics will change due to different end uses. In order to improve the legibility of text prints, low gloss paper is needed, but in order to obtain the best contrast in the reproduction of photographic originals, high gloss paper is also needed

III. consistency factor

the problem involved in consistency factor is: how much change can be allowed between various printing sheets? This is the printing process. We have set up special global business units for these industry markets and provide quality safety and stability issues in a variety of polymer product portfolios. With the increase of printing quantity, the printing time will be extended accordingly. During this period, the addition of various variable factors will inevitably be reflected in the printing quality. In addition, due to problems in the printing resistance of the printing plate, sometimes it is necessary to replace the printing plate in the middle, or it may be due to paper. The failure of blanket and printing machine had to stop halfway, which interfered with the original water ink balance. Once reprinted, the printing quality could not be consistent with that of the first printing

the following aspects should be explained about the changes between the printing sheets of printed matter:

first, the ability of visual differentiation over time. For example, in the standard observation distance, when the number of screen lines is 150 lines/inch, the maximum allowable value of registration change is 0.05mm. Beyond this range, changes in the image can be observed visually

second, the inherent characteristics of the production equipment will produce uncontrollable image variation. For example, the ink transmission mechanism of the existing offset or embossing machine cannot ensure that the same density is generated from front to back on the print sheet, and the density change on the same print sheet can reach 0.15

third, the allowable deviation limit. This needs to be determined according to the type of products and customer requirements. For example, newspaper printing can have large color changes, while cosmetics or food packaging products are not allowed to have large color differences

source: China tinplate printing

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