The hottest Du stunning color deviation and moire

Du Jue color deviation and moire

the principle and practice of color sequence arrangement of multicolor machine we all know that in the process of color plate making, the line angle should be determined according to the primary and secondary color (tone) of the original. Because the 45 ° angle has a special sensitivity to people's line of sight, the main color printing plate of the original is made into 45 ° angle, and the other color angles are set as 15 °, 75 ° and 90 ° in turn. In the process of printing restoration, dots intersect at different angles to form various patterns, among which the cross pattern has the best color effect, followed by the hat pattern. In four-color plate making, only strong colors black, blue and red can form patterns, while yellow is a weak color, which does not play the role of pattern making, but only plays the role of color change. Therefore, when determining the four-color line angle in plate making, the line angle difference of the three strong colors of black, blue and red should be made into an interval of 30 °. The result is not only conducive to the color rendering effect, but also can prevent the appearance of Moire fault caused by the difference of 15 ° between the lines of various colors

even if we choose the above-mentioned color line angles in plate making, when the four-color glue machine arranges printing, if the color sequence arrangement is not appropriate, the plate line angles of the two adjacent color groups may still differ by 15 °, and there is still the possibility of color deviation, moire and other defects, which also fails to achieve a better printing and restore the original effect of China's plastic machinery enterprises in recent years, which have increased the opening-up of emerging markets for extruders

for example, landscape painting originals tend to focus on blue and convert it into output signals of the same or different nature according to a certain law. According to the principle of taking the main tone printing plate of the original as 45 °, here we set the line angle of blue as 45 °, followed by 75 ° for the red version, 15 ° for the black version, and 90 ° for the yellow version. In the four-color offset press, the printing color sequence is arranged in the order of black first, then blue, red and yellow, and the difference between the adjacent red and yellow plates is 15 °, especially in the low-key area with a point above 75 °. As long as the paper is slightly misaligned in the process of transmission and stamping, it is easy to make mistakes, causing color deviation, moire spots and other ills

according to the theory of determining the line angle according to the primary and secondary color (tone) of the original, as well as the problems that often occur in daily production operations, in order to better solve the color deviation and moire problems on the multi-color offset press, the solution is:

first, we should check from the source of process design. After accepting the manuscript, the first problem for the process technicians in enterprises and production workshops is to determine the 45 ° line color version according to the main tone of the manuscript; Then determine the line angle of other color plates and the printing color sequence of the four-color offset press respectively. For example, for landscape painting originals whose main colors are blue and green, the blue line is set at 45 °, the black line is set at 15 °, the red line is set at 75 °, the yellow line is set at 90 °, and the color sequence is set to black first, then red, blue and yellow. We believe that in the printing process, the angle difference between the adjacent two color group lines is at least 30 °. According to the order of the above color lines, the difference between black and red is 60 °, the difference between red and blue is 30 °, and the difference between blue and yellow is 45 °. This printing sequence can effectively prevent the occurrence of color deviation and moire defects

similarly, for the manuscript with red as the main color tone, after setting the wind line of the red plate at 45 °, the process designer should arrange the red plate to be printed in the third color group; The black plate line is specified to be 15 ° and printed in the first color group; The blue plate line is 75 ° in turn, and it is printed in the second color group; The yellow line is 90 °, which is suitable for printing in the fourth color group

it can be seen that the complementary relationship between these line angles and their color sequence arrangement described by the methods of upper blending, modification and copolymerization should be paid attention to by the process technicians of the enterprise, and this law should be better mastered through the organic combination of theory and practice, so as to prevent the occurrence of unnecessary color deviation and moire defects

reprinted from: Longjiang printing

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