As a professional tin box buyer, you might have noticed one common phenomenon, that is color variance on custom tin printing. If you are peaky enough, it can be a headache; if you are understanding enough, you can smooth the whole tin printing process. If the colors are in pantones, they are deserved to be consistent; and this article only focus on colors in CMYK or full-color printing variance and tries to offer explanations with experience in tin box printing.
Mass Color V.S. Sample Color
You might always find that the mass printed tin colors are more vivid and brighter than the proofed tins. The reason is they are done by different machines, even though the printing files are the same: color proofing machine v.s. mass printing machine. Tin proofing machine is small, and the pressure to transfer the CMYK inks onto tinplate is limited; mass printing machine is big, offering enough pressure to precise the inks transferring. Therefore, in most cases mass colors are deeper and brigther than proof, and they reflect original design better.
What if you are insisting in the original proofed tin colors? No problem, the printing guy can modify (normally reduce) the CMYK figures on the printing models to match over.
Color Variance Between Different Printing Runs
If you order quantity is large enough to have separate model printing each time, it is a must to keep all the colors consistent for each run, and you are reasonable to request over 98% matching. If the order quantity is not large, different designs have to be pieced on the same model for printing on the same tinplate sheet, that is more colors to consider, the printing guy would mostly ensure the important colors (normally the one taking the large proportion on the sheet) matching up. If you are demanding all colors matching up, the printing guy would tick out the off colors, focus on them to print spot inks for better matching. There are ways to modify any off colors, no matter colors going deep or light, as long as the top covering finish (glossy or matte) has not been coated.
Color Variance on the Same Printing Run
For some designs, when printing, it is very easy to have “printing bump”, that when C M Y K four colors printed, two of them are bumped, then the same color on some areas goes deep, on other areas goes light; and colors go different even on the same tinplate sheet.
How to avoid this? To print next color after the front printed color being dried up, instead of print one after the other and then dry both colors together (All tin printing factories print two colors before heating in most cases – two printing machines set in front of heating oven). Unlike paper printing, tinplate printing needs high temperature heating for inks drying up. The dried tinplate can have the ink absorbed tightly. When the following color prints on the dried tinplate, it seldom bumps with the front ink. In this way it can effectively avoid the colors bumping, and then avoid the color variance on the same tinplate and on the same printing run.
Both paper printing and metal tin printing are offset lithography way, while the paper absorbs inks much faster than metal, the latter needs heating to assist inks absorbing and fixing, and heating temperature and times would also affect final colors affects. Thus, what you print on paper are what it looks finally; metal not. Tinplate printing still much depends on printing technicians’ experience and dedication. Great printing effects are key to tin boxes, to have clients’ full satisfaction and to maximumly control colors variance are what tin box suppliers need to pay high attention on.