Impressions - August 2014 - 70

tS

Digital Decorating

When manually pretreating a
garment for DTG printing, you simply need to
apply a mist of pretreatment to a garment.

An automatic pretreatment
machine takes the variable of inconsistent
pretreating away. It will pretreat each garment
exactly the same way each time.

the fabric at all; it is just resting atop the
pretreatment solution on the shirt and the
ink washes away, along with the pretreatment, in the ﬁrst washing.
It takes a little practice to get a correct print. When you change garments or
brands, you need to do more testing with
pretreatment application. That means a
little spoilage, and a little more time spent
on your craft.
In DTG classes, we demonstrate pretreating using a hand-held paint sprayer.
Remember, more is not better when it
comes to applying pretreatment.
You simply need to apply a mist of pretreatment to a garment instead of soaking
it with the solution. Using a hand-held
power sprayer, spray back and forth a
couple of times across the garment, taking
about ﬁve seconds to get the right amount
of solution on the shirt.
An automatic pretreatment machine
eliminates the variable of inconsistent
pretreating. If you have three operators
in your shop all pretreating garments, the
result will be similar to ﬁngerprints - no
two people pretreat exactly the same way.
An automatic pretreater will pretreat each
garment in exactly the same manner each
time. Dial in your ideal time/amount and
each shirt will be consistently pretreated,
thus eliminating the guesswork.

PRINTING ENVIRONMENT
Because DTG machines use waterbased ink, proper humidity is critical to
70

Impressions | August 2014

the process. You need to maintain at least
40%-50% humidity in the room at all
times. If your humidity level is below 40%,
you can expect ink-clogging issues in your
print head.
Your room temperature also is important. If it's too cold, the ink ﬂow will be
sluggish, resulting in dull images. Too hot
- in the 95˚F or higher range - and the
ink can start to dry up in the print head. A
typical ofﬁce temperature of 72˚F is ideal
for best results.

PRINT MODES
You generally have control of the
amount of ink applied in your white
underbase through your RIP software.
Maximum ink laydown commonly is not
necessary for a white underbase. Experimentation will help you pinpoint that
"happy place" where you achieve an ideal
bright white base with the least amount of
white ink required. Remember, the colors
are translucent, so it is imperative that you
have a crisp, white underbase before proceeding to the color pass on your machine.

CURING THE PRINTED GARMENT
Sometimes, a print will look great when
you remove it from the DTG machine, but
can dull during the curing process. With a
heavy laydown of wet ink, the heat press
could potentially press this wet ink down
into the fabric, resulting in a dull ﬁnished
product. To combat this, ﬁrst hover the
heat element over the image to achieve a

surface cure of the ink while keeping it on
top of the fabric. Second, cut back on the
pressure from your heat press. Medium
pressure is more than sufﬁcient to cure the
ink and maintain the image's brightness.
DTG printing on dark garments can be
challenging, but easily remedied. Achieving crisp, vibrant, dynamic ﬁnished images
on shirts can be attributed to: 1.) the proper shirt and fabric; 2.) the correct amount
of pretreatment; 3.) a good environment
for your printer; and 4.) laying down
enough white ink to achieve a bright white
underbase.
Terry Combs is a 35-year veteran of the
garment printing industry, and has managed
production shops large and small across
the country. He is the author of the ebooks
"Screen Printing: A Practical Guide" and
"Direct-to-Garment: A Practical Guide,"
both available at Amazon.com. For more
information, visit terrycombs.com.

Suggested

Reading

Like this article? Read these
other digital decorating articles at
impressionsmag.com:
* "Can You Make Money
with DTG?"
* "Go to the Dark Side"
* "Trends and Innovations
in Digital Heat Printing

impressionsmag.com
http://www.Amazon.com http://www.terrycombs.com http://www.impressionsmag.com http://www.impressionsmag.com
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