Impressions - January/February 2022 - 52

Here's a possibility: One shirt may
contain residual chemicals from the
manufacturing process that allowed the
pretreatment to bead on the surface. The
pretreatment sat on top of the fibers and
didn't soak into the shirt, giving it the
appearance of being oversaturated.
The other shirt may not contain these
chemicals, allowing the pretreatment
to immediately soak into the shirt and
spread out, making the shirt look just
slightly damp. The visual difference was
stunning.
A pretreatment machine affords you
A hand sprayer can produce a subtle
difference as opposed to an automatic
pretreatment machine, although spraying
by hand is more difficult.
repeatable, consistent application from
garment to garment. Spraying by hand
can be tedious and introduces a lot of variables.
Granted, a couple of grams may not
create disastrous results in your finished
product, but using a machine to apply the
pretreatment reduces operator error. In the
long run, it can save you time and money
while providing consistent results from
shirt to shirt.
Myth No. 3: Pretreatment Will Solve
All My Polyester-Printing Woes
There's this myth that is still extremely
prevalent in the market: " Do you have a
pretreatment that will let us print on polyester? "
The answer to that is more complex
than people want to realize. They want a
silver bullet to take down printing on red
polyester with no dye-migration issues.
This just isn't going to happen at this point
in the DTG industry.
Ask anyone who screen prints if they like
printing on red polyester. Or any polyester.
The problem is most DTG decorators
expect that the pretreatment will be the
magic bullet to make it possible while
eliminating any issues with dye migration
or pretreatment discoloration. The
problem is much more complex when it
comes to polyester.
One issue is the quality of the dyes used
in making polyester. When you have a red
polyester shirt and you wash it the first
couple of times, do you wash it with all your
other clothes or do you wash it separately?
One time of washing it with every other
piece of clothing and you'll learn never to
do that again, as all your other clothes will
come from the washing machine with a
beautiful pink hue.
The problem is often that the dyes used
are either poor in quality or improperly set
within the fabric. This results in dye transfer
or dye migration. This is typical when the
shirt and ink are heated to about 300˚F or
more (of course, this temperature can vary).
The dyes turn into a gas and migrate into
P.52
THE IMPOR T ANCE OF SHIR T QU ALIT Y
Shirt quality is another variable that should be considered when thinking about pretreatment.
There are many types of cotton and processes used to manufacture shirts. A standard black
shirt that just uses " available " cotton may require 35 grams of pretreatment for a 14 " x 16 " area
vs. a higher-quality shirt that uses a higher thread count (30 singles) of combed, ring-spun
cotton and is processed differently might only require 10 grams of pretreatment.
When you factor in all the costs associated with DTG printing, this can be a significant contributor
to the actual shirt cost. Even though a higher-quality shirt may cost more upfront for the
blank, you may save more money by using less pretreatment and ink due to the nature of the
higher-quality fabric.
the white ink film, making it appear pink.
Some people in the industry get around
this by curing the ink at a temperature just
below the point where dye migration can
occur, but that may not necessarily cure
the inks properly and can result in poor
wash fastness in the long term.
No pretreatment with favorable hand
and feel will be able to overcome fabric or
dye deficiencies that will result in white-ink
discoloration because of dye migration.
The professionals in our industry are
working on this issue, but the answer to the
problem won't just involve pretreatment.
Rather, it will encompass the shirts, dyes
and inks all working in concert with certain
processes and the pretreatment to make
polyester printing, without dye migration,
a possibility.
A Final Thought
Despite the pretreating myths that have
IMPRESSIONSMAG.COM JAN./FEB. 2022
endured throughout the years, approaching
DTG printing with realistic expectations
and the proper tools will allow
for newcomers and pros alike to become
proficient in their trade. Blindly accepting
myths or hearsay, and expecting dramatic
outcomes that are different than what
can realistically be achieved results in
decorators becoming disillusioned with
DTG printing.
The lesson here is simple: Don't let
the myths hold you down. 
Brian Walker has owned a screen-printing business,
developed quoting and pricing software, and also
launched a successful online direct-to-garment
equipment and supply business. He currently is
president of i-Group Technologies, makers of Viper
pretreatment machines for the direct-to-garment
industry, and founder and owner of RTP Apparel, a
supplier of ready-to-print garments for DTG decorating.
For more information or to comment on
this article, email Brian at brian@igrouptech.com.

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