There are two main requirements for the coating in the printing of custom square tin boxes: (1) The ink is required to have good adhesion and mechanical properties. Since the printed matter of the custom square tin box will eventually be made into food cans, toys, metal photo frames and barrels, and cans of chemical products, it needs to be cut, bent, and stretched, so the printing ink is required to have good adhesion to tinplate. and the corresponding mechanical properties.

In order to improve the ink adhesion, the tinplate of the custom square tin box needs to be whitened first before printing. White is the base color of all pictures and has high brightness. After adding other high-energy hues, the brightness of each hue can be improved to form a gradation.
(2) Requirements for white ink. The tinplate surface of the custom square tin box is silvery white (or yellow) with a metallic luster. Before printing color graphics, the surface needs to be whitened or printed. Due to the limitation of ink coverage, monochrome machines often need to be printed twice, and the whiteness can reach 75%.
Whiteness is an important indicator of the quality of tinplate printing products of the custom square tin boxes. It is required that the white ink has good bonding force with the primer, and will not turn yellow after repeated high temperature baking, and will not lose color after high temperature steam. Primer on tinplate can increase the adhesion with tinplate and has good bonding force to white ink.
Through the above introduction and analysis of Requirements for custom square tin box paint, hope it helps you.