How to control network expansion in plate making

In the color printing process, the percentage of the final dot is often a large percentage of dots of the color film, which is usually referred to as dot gain.
Dot enlargement has a great influence on the color and gradation of products. In the case of fixed printing conditions, different dot shapes and line numbers are selected. When color separation settings and printing are performed, full consideration is given to the status of the original (such as tonal adjustments. The balance of length and color) and the dot changes in the process after color separation, and correct compensation, can get a satisfactory replica.
Dot shapes are numerous, but dot types commonly used in color separation and color desktop systems are square, circular, and chain-shaped. The increase in the tone value of the dot shape in the proofing (or printing) process is different, which means that the longer the perimeter of the dot, the larger the dot enlargement; the smaller the perimeter, the less the expansion. The same amount of ink spreads onto the substrate. The smaller the spreading area, the smaller the dot expansion.
Square-shaped outlets expanded to round-type outlets at 50% of outlets, with the largest expansion of outlets. Below 78%, the expansion of outlets is the smallest, but it is not conducive to the dark tone of performance. More than 78% of round outlets are most likely to absorb ink. The anti-circular outlets (understood as the shape of the blank part after circular overprinting) had the longest perimeter, forming a lap at 22%, with the largest network expansion. Smaller outlets show larger outlets, which is conducive to medium and dark tone levels.
The use of counter-circles and circular nets for color separation, standard grayscale scales for hanging nets, and high-optical compression for counter-circular dots, with good performance in dark shades. In printing, high light areas (ie, small outlets) are subject to change in printing pressure or exposure to a large number of printing plates, resulting in high gloss areas that are susceptible to inking (ie, loss of small outlets). Small outlets must be real, blackness must be high, and printing exposure must be high. To be correct, the printing pressure should be adjusted well. Small outlets have good ink properties, which will greatly increase the original high-capacity capabilities of the printed products and reduce the loss of the high-light areas. When the outlets overlap, they should be consistent with the tonality of the manuscript, and the dot expansion should be as small as possible. Dark spots 80%-97% of the outlets should not be too early, too much ink, to ensure the transfer rate of the ink transfer process, control network expansion. The use of technologies such as FM network, make the network as far as possible to achieve the ideal network standards.
The number of screens for four-color prints is based on the surface properties of the paper used in the print. The number of coated lines on the coated paper can be higher, while the number of lines on the offset paper is lower. The thin network line has a much larger value than the coarse network line. It is more obvious than the increase value at the beginning of different network points. The increase value of the FM network point is larger than the amplitude modulation. The dot gain value is the upper tone value of the printed matter minus the corresponding tone value on the color separation sheet. Correct compensation in plate separation and printing is to ensure and improve product quality.
With the same number of outlets, the percentage of outlets with different percentages of outlets is: 10% to 50% of outlets. As the percentage of original outlets increases, the percentage of print outlets increases gradually, outlet expansion rate increases, and square outlet ratio increases. There is a large increase in the number of circular dots. From 50% to 90% of outlets, with the increase of the percentage of original outlets, the percentage of printing outlets has gradually decreased, and the reduction of square outlets has been larger than that of round outlets. From 10% to 90% of the outlets, as the percentage of the original outlets increases, the percentage of the outlets of the outlets gradually decreases, and the square outlets have a larger reduction than the round outlets.
The rules for the expansion of outlets with the same percentage of outlets and different number of outlets are:
The higher the number of outlets, the greater the percentage expansion of printing outlets, and the greater the expansion rate of outlets, and the larger the square outlets than the round outlets.
The smaller the percentage of outlets and the higher the number of outlets, the larger the percentage expansion of printing outlets, and the greater the expansion rate of outlets, and the larger the square outlets than circular outlets.
The higher the number of dot lines, the larger the percentage of area where printing dots expand and the larger dot size of square dots than round dot dots.
The smaller the percentage of outlets is, the higher the number of outlets is, and the larger the percentage of printing outlets is, and the larger the square-shaped outlets are than the round outlets.
As long as we select different platemaking technologies according to different manuscripts, control the size of outlets, the proportion of outlets, and the change of outlets (ie, the expansion of outlets), we can grasp the law of outlet expansion according to the suitability of printing, proper printing, and correct dot compensation. , we can guarantee and improve the quality of printing and improve the economic efficiency of enterprises.