Printing & Design Tips: April 2004, Issue #33

Color Shifts in Neutrals

When you are printing a 4-color publication containing color builds of brown, gray, or other earth tones and neutral colors, your colors can shift, and you can find yourself with a color-matching nightmare. Why might this happen, and how can you fix the problem?

First of all, the problem noted above occurs most often when you print equal (or almost equal) amounts of the three primary colors: cyan, magenta, and yellow. This would ideally produce a dark brown. However, if your printer increases any of these to fix an in-line problem (by, for example, adding magenta to fix a photo above or below the dark brown solid on the press sheet), the brown will take on a color cast. It may shift toward red or green.

The same is true for grays. If you want to print a neutral gray, and a color shift occurs, the gray can take on a pink or green cast.

Dot gain, which occurs to some extent in all offset printing and which is affected by the paper on which you print, can cause the same problem.

If you are expecting to match a specific dark brown, this can be disappointing, or if you are trying to build a consistent dark brown that repeats on successive pages, a color shift like this can be a disaster.

So, what can you do? Readjusting the color to remove the color cast seems like a good answer, but (in the example mentioned above) this could adversely affect the four-color photo above or below the dark brown solid on the press form.

A more effective solution would be to choose a match color for the brown (earth tone, neutral). For a gray, you can use a screen of black. Specifying a PMS match color would ensure a consistent brown (or other earth tone or neutral) throughout the run.

But this does cost more than four-color process work. It may even require you to print on a larger press with more ink units. If you cannot add a fifth color to avoid color shifts, discuss the placement of color with your printer. He may suggest changes in either the design of your piece or its imposition that would reduce the likelihood of in-line conflicts.

Another option you might discuss with your printer is undercolor removal (UCR). In this process, cyan, magenta, and yellow are reduced in neutral areas, and the black is increased an equal amount. Undercolor removal and its close cousin, gray component replacement (GCR), may not only reduce your ink costs (and makeready times) but may also increase the consistency of your neutrals.

PMS Color Doesn't Match the Swatch

Have you ever specified a match color (PMS) only to be disappointed when your print job arrives because the printed color doesn't match the color swatch? There are a few things to consider when choosing a match color to avoid disappointment.

First of all, consider the paper. If you are printing a match green on a bright white sheet, it will look a certain way. If you print the same green on an off-white sheet, it will look completely different. To make sure you are not surprised by the appearance of a particular ink on a particular paper, you can ask your printer for an "ink drawdown." The printer produces a drawdown by mixing your chosen ink and spreading a little on your chosen paper using a putty knife. While this thin film of ink won't show you how text or screens of the color will look, it will at least give you a general idea of the final appearance of your printed piece. This can be particularly helpful when you consider that many printing inks are transparent and are therefore dramatically altered by the paper color.

Second, consider the use of the color. If you print a solid green (as a background, for instance), it will match your color swatch. However, if you print a column of text (particularly one set in a small point size) in the same green, it will appear lighter than the color swatch. This is because you are printing a little green surrounded by a lot of white. Therefore, your eye sees a lighter green.

Finally, remember that the colors in your PMS book change over time and with exposure to light. Replace your color book periodically (the expiration date should be noted on the book).

When in doubt -- and this actually is always a good practice -- send the color chip to your printer along with the job. Even if the color has changed over time, you can ask your printer specifically to match the color on the supplied chip.

[Steven Waxman is a printing consultant. He teaches corporations how to save money buying printing, brokers printing services, and teaches prepress techniques. Steven has been in the printing industry for thirty-three years working as a writer, editor, print buyer, photographer, graphic designer, art director, and production manager.]