Impressions - January/February 2025 - 42

With proper curing, puff ink can add
depth to print pieces. Photo courtesy of
International Coatings
To achieve the thick layers of puff that were
incorporated into this print, the ink must meet
the correct temperature. Photo courtesy of
International Coatings
of the screen print process. Strive to streamline these critical
stages. It's kind of like looking into a restaurant's kitchen-a lot
can be learned about how the food will taste when you see the
kitchen in which it is prepared.
Are there pin holes creating little spots of ink on the garment?
These pesky little dots may not show up on your first few shirts or
even the first 1,000 shirts but can develop while the production
run continues. So, check your screens-and prints-frequently
throughout the day.
For the most part, these holes can be practically eliminated
by creating a clean, dust free and dry environment in all your
screen-prepping areas.
Create profiles for your coating and exposing department,
then create and maintain a proper ink kitchen. The profiles will
help keep your prints consistent from operator to operator and
from customer order to their reorder. This simple implementation
will save you countless hours and dollars over the years.
Monitor Constantly
Many printers try to make screen printing a " set it and forget
it " type of business, but it simply will never be. There are
countless things that can change throughout a production run,
whether it is a simple 100-piece run or 100,000-piece run.
The numerous factors involved make a " set-it-and-forget-it "
approach unrealistic, expecting the 1,000th print to be the
same as the first. Consistent monitoring is key.
Plastisol inks, for example, are thermoplastic, so you can
expect an ink that has been exposed to residual heat from
pallets that have passed through multiple flashes to change its
characteristics as printing progresses.
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ImpressionsMagazine.com Jan./Feb. 2025
At first, the ink will become creamier and thinner as the
squeegee agitates it by going back and forth. However, over
time it will start to thicken, or gel, as the heat from the pallets
affect sits thermoplastic characteristics. Thinning and thickening
will alter the ink's opacity and may cause variations to
your design throughout the duration of the production run.
The print you get at the end of the production run may not
look like the sample that was approved at the start.
Not all inks are created equal. Some brands may use a large
percentage of liquid thickener in their products, which can
exacerbate the problem. Inks containing liquid thickener may
start out thicker, but the ink will liquify to a thinner viscosity
during the production run. This additional factor could introduce
instability in the viscosity of the ink, which could in
turn affect the opacity of the print.
Another factor could be the weather. Let's say you have a job
for 100 shirts to print manually, which can be printed in one
day. In this case, you can assume the weather will be the same
from the first print to the last. If, on the other hand, you are
lucky enough to land a 100,000-piece job on an automatic,
then you may be printing the same image for 20 or 30-plus
days. (3,000 prints per day x 33.5 days is 100,500 shirts). Any
change in the weather over the course of the production run
can influence the garments' moisture content and the dryer
temperature.
If you are printing a large job, consider burning a second set
of screens to save on down time in case one of the screens rips.
It would be great if all the screens last over 100,000 prints, and
it may even be possible but...the cost of the extra screens pale
in comparison to the hour of downtime in case a screen (or
multiple screens) must be prepped for replacement.
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Impressions - January/February 2025

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