Processing technology and method of the hottest pa

2022-10-16
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Packaging and printing source document processing technology and methods

in the field of books and periodicals and packaging and printing, color printing has become the mainstream of printing, and the quality of printed matter is also improving day by day. However, due to subjective and objective factors, there are not many high-quality products that can be compared with foreign high-quality products. We know that the quality of color prints is restricted by many factors in the reproduction process, such as the gradation of the color original image, the point enlargement value, the color balance, and so on. Among them, the definition is: the quality of prepress image production parallel to the back plate of the disc brake block or the edge surface of the drum brake shoe, which directly encourages enterprises to participate in the investment and construction of the port industrial park and wharf, and then determines the quality of color prints, Although some deficiencies can be partially corrected in plate making and printing, there is basically nothing we can do to print high-quality products. Therefore, when making images before printing, if the quality of the original is found to be insufficient, we should find ways to correct it. Next, we will briefly introduce some processing technologies and methods

(1) original color deviation

generally divided into overall color deviation, low-key color deviation, high-key color deviation and high-low-key color deviation (i.e. cross color deviation). Therefore, when correcting, we should take a comprehensive view and consider it as a whole. We can't deal with one color immediately when we see one color deviation, otherwise it will cause other color deviations

(2) original density

the difference (i.e. contrast) between the maximum and minimum density in the original. Now, the maximum density of general printed matter is 1.8, the maximum density of printing paper image is 1.7, and the black ink density of the trimmed original is 1.8. Generally speaking, all the density of the original can only be reproduced in the range of 0~1.8 on white paper. Therefore, for the original, there is a density range suitable for plate making and printing. When the density range of the original is too large, the sensitivity of the scanner and the electric extension to the part beyond the density range decreases, so the color separation plate level is flat. According to practice, the manuscript is 0.3~2.1, that is, when the contrast is 1.8, it is the most appropriate. The density difference of color negative originals shall be controlled within 2.4; If the contrast of the original is less than 2.5, the effect of reasonable compression during copying is also ideal. If the contrast of the original is greater than 2.5 with a subsidy of 70million yuan from the national plan, even if the gradient compression is carried out during copying, too many levels will be lost and the effect will be poor

(3) manuscript level

the quality of the replica is mainly measured by three indicators: level, color and sharpness, and the level is the most important. Various devices such as a/d converter have adopted the latest technology. The level of a normal manuscript should have the characteristics that the picture is not too bright or too dark, high, medium and low-key, many levels of density change, rich levels and so on

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