Impressions - Digital Decorator - Summer 2015 - 26

By Terry Combs, Contributing Writer

Beyond the

DTG
Printer

How to achieve quality direct-to-garment prints.

here's something wrong with
the ink." "There's something
wrong with the printer."
"There's something wrong with..." a hundred
of other reasons direct-to-garment (DTG)
prints look dull, stiff or otherwise imperfect. Those of us in the world of DTG printing
hear similar statements nearly every day. As
with all things garment decorating, the first
thing we hear is, "It's the ink, or the machine,
or..." you get the idea. It's never me. It's never
something I've done.
In the case of DTG printing, there
is nearly always another reason for a
less-than-perfect image on your garment
rather than either the ink or the machine.
For the purpose of this article, we'll assume
we've started with a high-resolution, wellprepared piece of artwork (a dream job that is
subject for another article). If the image looks
perfect on one garment but not the next, our
search for an answer will go beyond the ink
or the machine.

PRETREATING
Just as with other garment decorating
methods, dark fabric DTG printing is where
the complications and level of expertise
reveal themselves. Based on personal expe26 § SUMMER 2015

rience with countless end users, pretreating
is the singular area of confusion and cause of
poor printing results.
Too little pretreatment will provide a dull
image. Pretreatment provides a barrier for
the water-based ink to set upon as curing
begins. An application of too little pretreatment, and the ink will absorb into the fabric
and appear dull or washed out.
On the other extreme, too much pretreatment will cause difficulties as well. As
with many things, the assumption can exist
that, "Some is good, therefore more must
be better!" This is not at all true with DTG
preparation for printing.
Too much pretreat will result in a stiff feel
on the shirt. This is the square or box that
some complain of with the assumption that
it is an unavoidable consequence of the process. In fact, this stiff square is caused by too
much pretreatment applied to the shirt, and
is by no means the "nature of the beast" as it
were when choosing the direct-to-garment
process of decoration.
A step further, more pretreatment may
have a more dire result. If the ink does not
bond to the fabric because of a heavy layer of
pretreat solution, then the image may wash
off the garment - the ink is printed on top of

a heavy barrier of pretreatment and not actually in contact with the fabric of the garment.
Many decorators will attribute this washout
problem to either the ink or the curing process. But, if the image washes off the shirt, it
is more than likely the result of too much pretreatment than any other cause.
There are a few choices when it comes to
application of pretreatment, but the most
commonly accepted methods as of today are
hand spraying with a power paint sprayer,
or by using an automatic pretreat machine.
First, you can achieve the same result using
either method, but more application errors
occur using one method over the other.
Using an automatic pretreatment
machine will give you consistency from
shirt-to-shirt. Which means, once you've
dialed in your ideal spray time/lay down
amount, you have repeatability. Plus, if the
machine is enclosed, you can operate it
near your direct-to-garment printer.
Hand spraying can achieve the exact
results, but it takes some additional time

Impressions - Digital Decorator - Summer 2015

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