Impressions - June 2018 - 40

Good pre-press equipment is critical
to achieving top-quality screens
quickly and accurately.
to achieve secondary and tertiary colors with four-color process
printing, combinations of the primary colors are printed on
top of each other. But in simulated process printing, secondary
and tertiary colors are printed directly through separate screens.
More screens are needed with simulated process printing,
since a white underbase and secondary colors, such as green,
orange and purple, are being printed with red, blue and yellow
primary colors, plus a highlight white. This explains why a
12- or 14-color press is needed to print some intricate simulated process designs. But this kind of printing enables mass
production of photorealistic designs on dark garments, such as
concert and biker tees, fashion apparel and more.
The Artwork
For the dress, Dane Clement of Great Dane Graphics provided
a design - stuffed animals in a wagon - from his online stock
clip-art collection.These designs already were color separated
for simulated process printing.
Art is the key to most popular garment lines, and most fashion printers have in-house artists to design fashion apparel.
According to Clement, any shop's new artist should spend time
on the production floor exposing screens and washing them
out. Not only should he be present when screens are set up on
the press, but he also should watch the entire printing process
to learn all the steps and see how everything works together.
Clement also recommends using Separation Studio to preview
art to see how it will look on a black background; if it looks
good on black, it will look good on all colors.
For this project, art was sized at 7 inches and a film positive
was printed.The size was too small for the dress, so Suhadolnik
resized it to 9 inches, then printed all six films.The dot size for this
design is a 55-line elliptical with the dot angles set to 61 degrees.
Clement designed this artwork to first print a white underbase
and flash, then print all the colors - wet-on-wet - on top.
"Printing wet-on-wet colors on top of the white underbase
helps mix the colors on press for more true color reproduction," he says.
Screen Selection
The screens contained aluminum frames and yellow 305 mesh
stretched to 25 N/cm, and were coated with Ulano Poly Plus
S with a one-on-one coating technique using the scoop coater's dull side.Yellow mesh is ideal for halftone printing to reduce
the amount of light scatter that causes undercutting during the
screen-exposure process.
Screen printing on fashion garments requires a different thought
process for mesh selection compared to traditional T-shirt printing.
For screen printing everyday vector art, 110-230 mesh counts
will handle most design requirements. But for fashion printing,
higher mesh counts in the 305 to 355 range commonly are used
to achieve the softest hand print and to enhance the fabric's drape.
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i m p r e s s i o n s m a g . c o m JUNE/JULY 2018

The screens had a stencil thickness of 20% emulsion over mesh
(EOM) and were measured with a stencil-thickness gauge.This
factor is critical to ensure that the correct amount of ink is deposited
onto the garment's surface.
Film Output, Exposure & Setup
The film separations were printed onto roll polyester film with an
Epson SureColor T3270 and pre-aligned on the screens with the
M&R Tri-Loc system.They were exposed for 50 seconds on the
M&R Starlight LED exposure unit and washed out with water
in a back-lit washout booth.
Good pre-press equipment is critical to achieving top-quality
screens quickly and accurately. Raster Image Processor (RIP)
software is needed to translate the halftones in the art files to the
Epson printer.We used AccuRIP software to output the art files
sent by Great Dane Graphics.
All six screens were loaded on the M&R Kruzer manual
screen-printing press, taped and registered in less than eight
minutes.The M&R Tri-Loc system was used to pre-align the
images in the same location on each screen prior to exposing.
Ink Selection
The three main ink systems used in fashion printing are plastisol,
discharge and water-based inks.Today's plastisols are easy to print
through fine meshes, resulting in a soft-hand print.Additives also
can be mixed with plastisols to achieve a feel that mimics the
softness of water-based inks.
Water-based and discharge inks are great for printing on
fashion garments, but it's important to have the right equipment. Requirements include a forced-hot-air textile dryer,
water-resistant stencil chemistry and a basic understanding of
printing with water-based inks so they won't dry in the screen
during production. Today's water-based inks are much easier
to use than those from 10 years ago.
For the print on this cotton dress,Wilflex Epic plastisol and
GSG'sVortex plastisol inks were used.A soft-hand additive was
not needed since the 305 mesh alone provided the desired feel.
It's important to periodically use a "donut" thermal probe to
check the printed ink's temperature as it passes through the dryer.
The curing temperature for standard plastisol ink is 320˚F. Always
follow your ink manufacturer's recommended cure temperature
for the product you are using.
Here's how to use a donut thermal probe: Print a design on a
swatch of test material with standard plastisol ink and press the
probe's crosshairs into the wet ink deposit. Run the fabric through
the entire length of the oven to allow the ink-film temperature
reading to reach 320˚F. If the temperature doesn't reach 320˚F,
increase the oven's temperature or slow down the conveyor belt
until a reading of 320˚ F is achieved.
Simulated process printing can be easy when you have great
artwork, printing equipment and use steps similar to the following:

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Impressions - June 2018

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