In commodity packaging and label printing, gold ink is often used to realize the printing of golden graphic and text, and gives people the impression of exquisite, colorful and noble. Guangzhou plastic box printing, as a special printing method, is slightly different from ordinary ink printing methods in the application of transparent plastic box printing materials and processing operations.

 PET plastic box printing generally adopts a neutral or neutral hard lining, and the pressure of the ink roller on the printing plate can not be too large, otherwise it will cause the phenomenon of stencil printing.

 When the PET plastic box is printed, the ink layer on the printing plate often lacks the amount of ink even when exposed to the surface of the paper or other substrates. Therefore, in order for the gold ink to reach a saturated state, it fully exhibits its unique metallic luster, and generally adopts a secondary printing method. At present, there are two basic methods of secondary printing: the first is to print fake gold ink as the background color, and then to superimpose gold ink; the other is to directly print gold ink twice. The fake gold ink used in the former method is generally prepared by using yellow yellow or medium yellow yellow ink as the main ingredient. If the paper is loose on paper and the paper surface is flat, the false gold ink is mainly yellow, and it will participate in the appropriate amount of gold ink.

If the paper is tight and the paper surface is smooth, clear yellow and a small amount of gold ink are used to allocate false gold ink. When printing, the amount of background ink should be as small as possible, with the principle of not revealing the bottom and not seeping. When the undercoat ink is not completely dry, the ink is overprinted and the amount of ink can be slightly larger, so that the talent can reach the saturation state of the gold ink. When adopting the latter method, it is also necessary to emphasize that it is appropriate to overprint the second pass of gold ink when the first printing of the gold ink is not completely dry. This is because the gold powder in the gold ink is a metallic pigment. Dry and reprint, the particles are not easy to stick.