Impressions - August 2015 - 60

Screen Printing Technique

MAKING SENSE OF MESH
Just as squeegee hardness affects ink
deposit, so does mesh count. The lower
the mesh count, the larger the ink deposit.
But are there any other features differentiating one mesh type over another?
Thread Count: As most printers know,
mesh controls ink flow once the squeegee
passes over the image. The general rule of
thumb is that the lower the mesh count
is per inch (or centimeter), the larger the
amount of ink flow. However, there are
some instances where it is possible to have
more threads per inch/centimeter and get
an even larger amount of ink flow. How so?

A Quick
Mesh Guide
This simple guide that will help in
choosing the right mesh counts for
specific jobs:
Mesh Count: 25, 40
Usage: Coarse glitter inks.
Mesh Count: 60, 86
Usage: Specialty inks, such as puff or
high-density, fine shimmers, glitters
or metallics.
Mesh Count: 110, 155
Usage: Where a large deposit of ink
is needed, such as athletic numbers,
printing white on black fabric, lowdetail art or heavy white ink.
Mesh Count: 160, 180, 200
Usage: Printing underbase white
to create a softer overall feel,
good medium-sized mesh count
for medium-detailed artwork. The
200-count mesh can be a happy
medium screen selection for when a
230 mesh is too fine and a 155 mesh
is too coarse.
Mesh Count: 230, 280, 305
Usage: Low ink deposit, works
well for halftone printing, simulated
process or CMYK process printing.
Mesh Count: 355
Usage: Low ink deposit, generally
used by experienced printers only.
Often used for printing 65-line or
higher halftones for detailed images.

Impressions | August 2015

Shown are squeegee blades with different durometers, as well as some composite blades
consisting of several durometers sandwiched together. Blade samples courtesy of Fimor, Serilor brand.

Thread Diameter: Not all meshes at
the same thread count function identically. This is because of the actual thread
diameter used to create the mesh. Obviously, the thicker the thread diameter, the
higher the tension you can achieve when
stretching the screen. Thicker thread also
is less likely to cause the screen mesh to
pop or break.
Breaking mesh is bad, right? Yes, but
you have options to consider. Some mesh
is made with thinner thread diameter
(with the same mesh count) and - if used
with care - won't have to be stretched to
such a high level as the thicker thread.
Also, for the same mesh count, the thinner thread diameter allows for a greater
percentage of open area within the mesh,
resulting in higher image definition and increased ink flow. So if the thread diameter
is smaller, a higher mesh count still can be
used to achieve a larger amount of ink flow
and finer detail in the print.

PUTTING IT ALL TOGETHER
It's hard to explain the complex relationship that occurs when the squeegee
touches the ink and applies it to the shirt.
A soft squeegee pushing low-viscosity
(thin) ink through a coarse screen can
apply too much ink. But use that soft
squeegee to push a thick ink through a
fine mesh and it can spell disaster.
Similarly, when a hard squeegee is used
to push thin ink using an open mesh, or

if the same hard squeegee is used to push
thin ink with a lot of pressure through a
fine mesh, both scenarios may result in
less-desirable printing outcomes.
Knowing how each tool can affect the
outcome of a print, you can adjust the
variables to make bad ink look better or
good ink look outstanding. I liken printing to an art form, where a good printer
can use his tools to create the best possible print. Much of the finesse in screen
printing comes only with experience, but
knowing the basics about how different
tools can affect different aspects of the
print outcome is half the battle.
Kieth Stevens is the Western regional sales
manager for International Coatings. He has
been teaching screen printing for more than 10
years and is a regular contributor to International Coatings' blogs. For more information,
visit iccink.com and read the company's blog
at internationalcoatingsblog.com.

Suggested

Reading

Read more screen-printing articles
at impressionsmag.com.
* "Loading Shirts Onto an
Automatic Press"
* "5 Tips for Printing on Fleece"
* "The Importance of a Clean
Ink Kitchen"

impressionsmag.com

http://www.iccink.com http://www.internationalcoatingsblog.com http://www.impressionsmag.com http://www.impressionsmag.com

Impressions - August 2015

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