Custom Printing: The Printing Substrate Changes the Ink Color

The more I study the various visual arts, the more similarities I see between and among them.

My fiancee bought some hair coloring today, and noted that the final color will depend on the original hair color of the person using the product. She had chosen a bright auburn shade, and on the back of the package I saw three slightly different final colors based on whether the original hair had been light to medium blonde, dark blonde to light brown, or medium to dark brown.

Presumably, the purpose of such an explanation was to tell the user what to expect. But to me it brought to mind the differences in color output when offset custom printing (or digitally printing) on a white sheet, beige sheet, or much darker sheet. The substrate always affects the color of the printed ink.

My fiancee went on to explain how eyelash coloration works the same way. The color you apply with a brush will look different on women with different original eye lash colors.

How Does This Apply to Commercial Printing?

Here are some thoughts pertaining to a number of different custom printing situations and technologies:

1. 1. When you have chosen an off-white press sheet onto which you will print your four-color process job, remember that process inks are transparent. If your photos include faces, the flesh color will be affected by the underlying paper, and the overall effect may be yellower than you would like. To compensate for this you can have the printer add a layer of opaque white beneath the process colors. (This will add to your overall cost, of course.) I have also seen this done with a metallic silver ink as a base and with opaque white actually mixed in with the process colors.

1. 1. Another approach if you’ve chosen a cream stock and you want to print white lettering on the paper is to use white foil rather than ink. Foil will completely retain its surface consistency (unlike ink) because it will not seep into the paper. After all, the white foil is attached to the surface of the paper with heat and pressure. If you choose this option, you will need to pay extra for the metal die used to cut the white foil.

1. 1. If you’re printing on a black t-shirt, the underprinting of white ink will make a huge difference in the final color. In this case the opaque white will provide a consistent, light background for any subsequent colors you may add.

1. 1. Printing on clear acetate will benefit from the same approach. Let’s say you’re producing a large-format section of a movie standee, and you want a transparency effect. Printing the inkjet inks or custom screen printing inks directly on the clear acetate will dull down the colors significantly, but laying down a background of opaque white will provide a bright background which will reflect back to the viewer the light that travels through the transparent process colors. The viewer’s eye will interpret this as increased vibrancy within the inks.

1. You should know that large format inkjet presses (both the flatbed variety and also the roll-fed presses) will usually have an additional ink reservoir for an opaque white ink. In addition, the inkjet presses have been designed to lay down the white background precisely positioned under the color overprinting. Therefore, this technology makes printing on either a colored background or a transparent background a viable, attractive option.

What About Proofing Your Print Job?

If you’re printing process colors over a colored background, then visualizing the final outcome will be a challenge. Your computer monitor will display color on a white background. Of course you can add a tint to the background of your job to match the paper, but this might not give you a completely accurate view (remember to remove the tint screen before printing).

What I’ve always done is ask the printer or paper merchant for printed samples that match my stated goals for the substrates and inks. It’s easier to communicate using a physical printed product. In addition, if the printer has produced a job you really like, you can always ask for help in preparing the art files to ensure that your job will be as successful as the one your commercial printing vendor just produced.

Another approach you might find helpful is to inkjet print a proof on the paper you have chosen for the final job. This is particularly useful if you’re printing process colors on a cream substrate. While not 100 percent accurate, this will at least give you a better idea than a screen view of how the final job will look.

If you’re flush with cash and your product needs to be perfect, you can always request a press proof (a few copies produced on a small press). However, this is an extremely expensive option since you’re really printing the project twice (once for the proof and once for the final job).

This entry was posted on Wednesday, October 28th, 2015 at 3:58 pm and is filed under Paper and finishing. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.