Printing Du Jue ColorDeviation and Moire

       Because the 45 ° angle has a special sensitivity to people’s line of sight, the main tone 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, the dots intersect at different angles to form various patterns, among which the cross pattern has the best color effect, followed by the monk hat pattern.Printing Du Jue ColorDeviation and Moire

       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 formation, but only the role of color change. Printing Du Jue ColorDeviation and Moire

      Therefore, when determining the four-color screen wire angle in plate making, the screen wire angle difference of three strong colors of black, blue and red should be made into an interval of 30 °, which is not only conducive to the color rendering effect, but also can prevent the occurrence of Moire fault caused by the 15 ° difference of each color screen wire.Printing Du Jue ColorDeviation and Moire

     Even if we choose the above-mentioned screen line angles in plate making, if the color sequence arrangement is not appropriate, the screen line angles of the printing plates 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 will not achieve a better effect of printing and restoring the original.Printing Du Jue ColorDeviation and Moire

       For example, the original of landscape painting tends to focus on blue. According to the principle of taking the main color printing plate of the original as 45 °, here we set the screen angle of blue as 45 °, followed by 75 ° for the red version, 15 ° for the black version and 90 ° for the yellow version.Printing Du Jue ColorDeviation and Moire

       In the four-color offset press, the printing color sequence is arranged in the order of black first, then blue, red and yellow, the difference between the adjacent red and yellow plates is 15 °, especially in the low-key area with dot above 75 °, as long as the paper is slightly misplaced in the process of transmission and embossing, it is easy to cause defects such as wrong screen, color deviation and moire spots.Printing Du Jue ColorDeviation and Moire

     According to the theory of determining the screen wire angle according to the primary and secondary color (tone) of the original, as well as the problems often occurred in daily production operations, in order to better solve the problems of color deviation and moire on the multi-color offset press, the solutions are as follows:Printing Du Jue ColorDeviation and Moire

      First of all, we should check from the source of process design. After the process technicians in the enterprise and production workshop accept the original, the first problem is to determine the 45 ° screen color plate according to the main tone of the original; Then determine the screen angle of other color plates and the printing color sequence of four-color offset press. Printing Du Jue ColorDeviation and Moire

       For example, for landscape painting originals whose main colors are blue and green, the blue screen line is set at 45 °, the black screen line is set at 15 °, the red screen line is set at 75 °, the yellow screen line is set at 90 °, and the color sequence is black first, followed by red, blue and yellow. Printing Du Jue ColorDeviation and Moire

       We believe that in the printing process, the screen line angles of adjacent two color groups differ by at least 30 °. According to the above order of screen 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 order can effectively prevent the occurrence of color deviation and moire defects.Printing Du Jue ColorDeviation and Moire

     Similarly, for the original with red as the main tone, after setting the wind line of the red plate at 45 °, the process designer shall arrange the red plate for printing in the third color group; The black screen line shall be 15 ° and printed in the first color group;Printing Du Jue ColorDeviation and Moire 

       In turn, the blue screen line is 75 ° and printed in the second color group; The yellow screen cable is 90 °, which is more suitable for printing in the fourth color group.Printing Du Jue ColorDeviation and Moire

      It can be seen that the complementary relationship between these network cable angles and their color sequence arrangement should be paid attention to by the process technicians of the enterprise, and better grasp this law through the organic combination of theory and practice, so as to prevent the occurrence of unnecessary color deviation and moire defects.Printing Du Jue ColorDeviation and Moire