Screen Printing - February/March 2018 - 31

FIGURE 8

combinations might yield rather than
just guess. For a high-volume job, the
extra effort can pay off. Even black
shirts can vary from one manufacturer
to another, with dyes that can skew
toward another color like magenta or
blue and that might produce a different hue than you expect.
Another common challenge
where this technique can help is
grunge artwork that has a lot of
FIGURE 9
tiny splatters or distressed pieces,
like the shirt in Figure 8. This
type of design can cause some real
headaches with registration and/or
screen stretch on press between
the underbase screen and the
overprinted colors. Here, using an
alternate underbase color can save
Remember that when you create
a lot of profit. Those tiny image eleseparations using an alternative
ments will be similar in color to the
underbase, you will need to pull a
underbase, eliminating the registraslightly more saturated color for the
tion concerns and allowing setup to
accent or top-printed colors because
go much faster. The main concern is
the underbase will change them,
if the colors from the original design
making them slightly duller and/or
that you'll be overprinting are too
changing their hue. As with most
bright for this to work.
color mixing, avoid using a color
A final challenge that an alternate
for an underbase that might blend
underbase can make easier involves
with an overprint color to create
full-color designs that are intended
an unwanted end result (such as a
to have a washed-out look, such
light green underbase and a magenta
Nonwhite underbases can be an effective
as the one in Figure 9. Imagine
overprint, which would combine to
technique to employ for grunge artwork with
a vintage wine label with a lot of
create a gross brown).
a lot of splatters [Figure 8] and washed-out
colors. You want to print it on a tan
Be careful promising this process
designs [Figure 9] that require more subtle,
softer prints.
shirt, but the artwork has a dull look
to a client in the art approval stage if
to it as though it has been in storage
you haven't tested the color combifor years. This would be a good situation to use an off-white
nations first. You may have to make some on-press changes the
underbase to help dull the top colors, making the print softer. It
first few times you attempt an alternate color underbase. You
would also make the entire production process simpler because
don't want to have to revise your separations multiple times on
you could use regular, semitransparent colors and just let the
a rush job for a picky customer.
underbase and shirt create the washed-out look. You may have
Another time you may need to use an alternate underbase
to test it to get the right underbase color, but it would be a lot
involves art with image elements that fade off into a dark shirt.
Imagine a brick wall that slowly fades into the shadows on a black easier then custom mixing all of your top colors and printing
shirt. With such a design, it might be advantageous to use a mauve them on a white underbase.
Printing an underbase with a color other than white can
or slightly reddish-gray underbase because it will make for a more
be an effective and useful way to cut the number of colors in
subtle, less heavy print. It also prevents the white underbase
a job, reduce setup time, and prevent press headaches. You
showing through as it fades out into the shirt background.
just need the right design combined with some experience.
Some printers design this type of artwork so that one or more
Take the time to test variations of the press setup, inks, and
of the overprint colors print off the underbase and directly onto
separation methods so you can plan and anticipate the results
the shirt in parts of the image. This is an advanced technique and
you might get the next time you're presented with a duotone
it's vitally important to test, especially with shirt colors other than
black. I've gone so far as to get samples of such shirts and then test or grunge design. With enough practice, this process can be a
valuable solution that will provide great prints that are softer
print the underbase and overprint colors for the job, reducing the
and more easily color matched to the original artwork.
opacity of the underbase in stages so I could see what different
6 percent for the top color channels and around 80 percent for the
underbase channel. You can then
turn on the "eye" in front of each
channel in the same order as the
print sequence you are planning
and view a digital approximation
of how your separation will print.
This won't be a perfect match, but
it will give you an idea if there are
any bad areas or spots where the
underbase is showing. You can
view your design in stages with
each color turned on in sequence
to catch errors and see if the
alternate underbase appears to be
working. (See Figure 7.)

FEBRUARY / MARCH 2018

Table of Contents for the Digital Edition of Screen Printing - February/March 2018