The plate making method of metal portrait printing is the same as that of paper printing, and there are special requirements for the characteristics of tin can printing:
1. In metal portrait printing, due to the non-absorptive nature of the substrate tinplate and the hardness of the tinplate sheet, the deformation of the dots is more obvious than that of the paper during the tin can printing process, especially in the dark and midtone areas. The skip level becomes deeper, the dark tone changes and upgrades sharply, and the use of square dots is more obvious, while the sudden change of midtones is alleviated by diamond-shaped or circular dots. The reproduction of printed iron dots is more favorable.
2. Because the tinplate is well printed, it still needs to be processed by stamping and forming. Therefore, in the process of metal portrait printing and plate making, it is necessary to reserve space such as welding seam edges to ensure that the text pattern does not deviate from the center after processing and stamping.
3. For all welded finished products such as pressure tanks, the seam edge of the aerosol can printing cannot have pictures and texts, which can ensure the needs of subsequent welding.