Printing Your T-shirts: An Overview
Mandar

You've picked your textiles, created a t-shirt design and
placed your order. So what happens next?

The first step in getting your design onto a t-shirt involves
printing films for the various colors used. A graphic artist
will look at your artwork and determine the best method of
printing the colors.

The two main methods of printing colors are spot colors and
four-color process. Spot colors are individual colors that are
printed separately. There are 100's of pre-mixed colors and an
infinite number of colors that can be mixed to specification
(e.g. Pantone Matching System colors).

Four-color process physically blends four colors (Cyan (sky
blue), Magenta (hot pink), Yellow and Black) on the textile to
create a large variety of colors. Four-color process, also
known as CMYK, is used to simulate photographic work and
graphics with sophisticated shading and textural effects. A
hybrid form of printing known as simulated process is sometimes
used, combining components of both process and spot color
printing.

The graphic artist creates transparent acetate films of each
color and prints them in black along with registration marks
and identifying information. The films are then collected into
an envelope with printing instructions and sent to the be
burned onto screens.

Each color of your t-shirt design is then exposed via a
high-intensity lightbox onto a fine mesh screen that has been
coated with photosensitive emulsion. These screens were
initially made from silk, thus the origin of the term
silkscreen. When the emulsion is exposed, it hardens and
becomes insoluble to water. The black sections of the acetate
film prevent light from getting to the emulsion immediately
beneath them. Those sections not exposed will dissolve in
water. The screen is placed in a high-pressure washing unit
where the unexposed sections of emulsion are washed out of the
screen. What remains is, in effect, an intricate stencil for
that particular color of ink.

While the Art Department is working on your films, your
t-shirts are being ordered from wholesalers. Sometimes this can
be a challenge; calls can be made all across the country looking
for a particular size or color of t-shirt. When the textiles
arrive, they are counted in and checked against the order for
accuracy and then taken to the screen printers.

A multiple-head press holds a number of screens from as few as
four to as many as sixteen. The screens are arranged radially
and rotate over palettes that the t shirts are loaded on. There
are both automatic and manual presses; on automatics the
rotation is handled by pneumatics while smaller manual presses
are physically rotated by the printer. Each screen is placed
onto a bracket, or head, and locked into place. The printer
then carefully adjusts the printed images from each screen
until they are all in correct alignment for the final, combined
image. The correct color of ink is added to each screen and is
forced through the screen's openings by pulling a squeegee from
the bottom of the screen to the top. A number of different
factors affect the final silkscreen print result, including the
hardness of the squeegee, the angle and force of the pull used,
and the type of ink used.

After printing, your t-shirts are run through a
high-temperature dryer to cure the ink so it will bind to the
fibers of the material. A final test print is approved by the
graphic artist working on your design, and the run of t-shirts
is printed.


About The Author: Mandar is a graphic artist and man-about-town
with Expertshirt.com. Design your own custom t-shirt online at
http://www.expertshirt.com