Factor 1 of the most popular network increase

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Factors of dot increase (I)

in the printing process, dots are generally taken as the basic unit. Because the dot itself is very small, it is always changing after being added, printed and printed on paper. It causes the change of the tone of the whole picture and affects the quality of the printed matter. The main change is the increase of dots. Point increase includes optical increase and physical increase. Optical amplification is caused by the reflection and diffusion of light, which causes the visual area formed by entering the human eye and reaching the visual film to be larger than the actual area of the point. Physical increase includes the increase of printing pressure, insufficient exposure of plate printing, and the increase of dots caused by ink absorption and diffusion caused by the characteristics of paper and ink. Physical increase is the main form of point increase, which can be reduced by changing the printing conditions

according to the geometric point increase, the edge part expands outward evenly, and the radial increase value of points with different percentages is consistent. For example, 10% point increase (false edge) is 10 μ m. The increase value of 90% point is also 10 μ m。 However, in the actual printing transmission, because the side length of different points is different, the coverage ratio of point increase is different. The coverage area is the largest when the square point is increased by 50%. When the point area is 10% - 50%, the increase occurs at the edge of the point; More than 60% of the dots increase in the black circle, that is, the white dots shrink

The increase of

points often leads to the darkening of bright and intermediate tone levels in the image, and the merging of some dark tone levels. If you don't deal with this problem, it's useless to make any more gradient adjustments to the image. Therefore, we should fully consider the impact of various factors in the process of plate making and printing on the increase of weak points in the development of enterprises, and set a compensation number in advance to compensate for the increase of points in printing

1. Factors affecting point increase

1. Influence of printing conditions on point increase

the area of the midpoint in the printing process will increase differently according to the change of printing conditions. Under normal printing conditions, in order to maintain the appropriate current contrast of the picture, there must be sufficient ink volume and appropriate pressure, so the normal point increase in the future is inevitable. However, too much ink volume and pressure regenerate the road area of 386000 square meters, which will increase the number of points too much, resulting in the picture level and level into waste products

2. Effect of ink layer thickness on dot increase

when ink dots are transferred from the printing plate to the blanket, and then transferred to the paper, the ink layer has a certain thickness and is a soft body, so the dot must increase after being pressed. The degree of increase varies according to the amount of ink, so the amount of ink must be strictly controlled. If too much or too little ink is used on the printer, the halftone dots may be filled with ink due to dot increase, or completely "exposed". If the ink balance is out of balance, the same phenomenon will happen. Because the ink is sticky and wet, printing a lot of ink on paper may cause wrinkling and sticking to the ink film may also cause various troubles. Therefore,

in image processing software such as Photoshop, it has the function of removing UCR and replacing GUR with gray components in the background color, which can delete the colors of various inks, and reduce the overall percentage of inks to a reasonable value (usually between 240% and 360%), and the specific value depends on the type of printing machine, paper condition, etc. (to be continued)

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