1. Put the positive film on the glass plate, and then expose it. Put the stretched screen on the positive film, parallel to the image axis. If moire patterns appear, rotate the screen to the left or right until the moire patterns disappear, generally turning 7°. The area where the moiré is easy to form is located in the direction of the wire mesh and the intersection of the wire mesh. Main colors and darker colors cause more problems with moire.
2. A basic requirement to achieve perfect image reproduction is that the quality of the transparent positive film should be good, that is, the edges of the dots should be neat and opaque. The color separation film and the printing ink used to use the same color scale.
3. A well-ground squeegee is essential for high-quality printing. The hardness of the blade is about 70. The squeegee should be set at an angle of 75°. If the angle of the squeegee is adjusted too flat, the printed image may be blurred. If the angle is adjusted too steep, the risk of screen-printed image distortion is high.
4. For four-color printing, aluminum screen frames of the same size and stability should be used, and all screen frames used are stretched with screens of the same type and model. The use of a dyed screen helps to eliminate the moiré pattern. The tension of the screen should be uniform and the tension of the four screens of the four-color printing is the same.