Impressions - June 2018 - 37

Notice the coverage difference
when using various squeegee
durometers.The wing on the left
was printed with a hard squeegee.
The version on the right was
printed with a soft squeegee.

on the print - such as the mesh imprint - or cause the image to be blurry.
The larger the image being printed, the
more pronounced the blur can become
if off-contact is not set properly. Also,
the lower the screen mesh's tension, the
more off-contact will be needed to get
the screen to peel off the substrate, which
can add to the blurriness.
Screen Tension: If your screens are
very loose, get them restretched as soon
as possible.Your local dealer can help you
with this. In the meantime, order a few
new screens of your favorite mesh counts.
Simply put, printing is much easier with
tight screens.
Registration and off-contact magically
become less of a problem as well. Just be
sure that all the screens being used for
a particular print have the same - or
similar - tension values. For example, if
a five-color job's registration is off, check
to see if all the screens are in the same
tension range. If one is lower than the
others, it is probably that screen that's
causing the registration issue.
Shirts Moving on Pallet During
Printing: It can be frustrating when a
shirt shifts as the pallets move between
screens when you're in the middle of
printing a design. It may mean you have
to start a job again from the beginning.
Research the adhesives that are offered
by industry suppliers. Some are sprayed
or squeezed out of a bottle, while others
come in a bucket and can be spread onto
the pallet. Do some homework early in
your garment-decorating career to find
the right type for your shop.
Most water-based adhesives are less
affected by the flash unit's heat than the
aerosol ones - even those that claim
to be specially made to withstand heat.
Ink-Deposit Issues
Squeegees: These commonly overlooked
tools can greatly impact print quality. If
you are printing on a manual press, remember to properly flood the screen
before each print. The flooding action
pushes the ink into the area that is to be
printed and does half the work. When
you actually print, you should only be
applying the ink onto the shirt.

If you don't flood the screen before
each print, then you would have to add
pressure on your print stroke, which could
force the ink into the fabric, thus wasting
energy, ink and profits. Every automatic
screen-printing machine floods the screen
each time before the squeegee prints.
Additionally, maintain a sharp squeegee
edge. This helps to shear or cut off the
ink, allowing it to more easily release
from the screen. If the edge is worn or
rounded, it makes it harder for the ink to
clear the screen and can make the print
feel rougher. Replace any squeegee blade
that has nicks.
Keep an assortment of squeegee durometers in your shop. If you need more
ink deposit on a print that lacks good
coverage, switching to a softer squeegee is a
quick option. Otherwise, double-printing
a color may be necessary, thus slowing
production and costing more money.
Similarly, if less ink deposit is needed,
switch to a harder squeegee.Also, adjusting
the squeegee angle can add or reduce the
amount of ink being applied. For example,
angling the squeegee toward the direction
of the print stroke adds more ink deposit.
And always be consistent with pressure so

that troubleshooting will be easier when
a print goes awry.
Emulsion Stencil: Another underappreciated part of the printing process
is emulsion quality. Emulsion over mesh
(EOM) is the emulsion thickness of the
coated screen vs. the uncoated screen.
It's important to have a thicker emulsion
deposit on the bottom of the screen's
shirt side.When using finer mesh counts,
less emulsion typically is applied, but it is
important to have more emulsion applied
on the bottom of the screen with lower
mesh counts.
This is crucial because extra emulsion
acts like a gasket to hold back the ink
that is being squeezed through the screen
under pressure. Otherwise, the ink can
go anywhere, even under the gaps of the
screen weave.The resulting print can have
ragged or uneven edges due to ink gain.
Having a suitably thick emulsion stencil
also helps eliminate mesh marks while
increasing opacity.
What about the finer meshes? If there
is not enough emulsion on the bottom
of the screen when printing halftones
and fine detail, the halftone dots may be
distorted, appearing in the shape of stars.
JUNE/JULY 2018

P.37
Impressions - June 2018

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