In general, spot colors are printed in the field, and they are rarely processed at the outlets. Therefore, the point of spot color screening is rarely mentioned. However, when using a lighter mesh color, there will be problems with the design and modification of the spot color screen dot. If the spot color of a dot has the overprint area following the colors printed by other dots, the spot color screening problem must be considered.
At this time, if the angle formed by the spot color screen's screen angle and other color screen angles is less than 30 degrees, it will cause the screen to generate moiré; if the angles overlap each other, it will cause ink overprint problems, which will cause prints The color is seriously distorted.
In addition, the screen angle of spot colors is generally preset to 45 degrees in software (45 degrees are considered to be the most comfortable angle for human eyes, so that the dots can be arranged in the same direction as the horizontal and vertical lines. The ability of the human eye to detect dots, if it is a two-tone image or data file, which is printed with four colors of black (usually in four-color screen printing, the black dot is placed at 45 degrees, yellow is 0 degrees, Magenta is 15 degrees, green is 75 degrees,) there are spot colors, or there are more than two spot colors, then in the color separation screening will be output at 45 degrees, so when using shallow network for spot colors, if There may be overprinting with other screening colors. You must open the software color setting or print setting dialog box when the color separation is output to modify the spot color screening angle.