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.]