If you’ve ever attended an industry trade show or opened one of the garment printing magazines, you’ve seen everything from one color manual machines to multi-color automatic presses.
You can even build a press yourself if you’re handy enough, and achieve
very similar results. This is the true beauty of the screen printing
industry. You can achieve the same result from the least
expensive to the most expensive equipment. It all comes down to
efficiency in the end. An automatic press is far better to
print a 10,000 piece order, but that same automatic press is not your
best choice to print a 24 piece job. There’s a place for all.
“Anyone with a two car garage has the potential of being a screen printer,” I often tell students.
And
it is absolutely true. You can compete with the biggest printer, as
long as you learn the process, and do what is necessary to output a
first quality product. The possibility and potential is there, but the
effort will be all up to you.
The number of colors available on a press means the number of screens that you can set up at any one time. A four-color press
has the potential of printing up to a four-color job. If you haven’t
purchased a press yet, and you can afford the price, I highly recommend
you purchase a six-color press. Will you print mostly six-color jobs?
Not very likely. But you will have the potential of printing most any
job, including full color photo quality images on dark shirts with a six-color machine.
Those full color images are beautiful to look at, and a great goal for you to aspire. But the bread-and-butter for most screen printers will be one and two-color work
for local business, clubs, schools and anyone else who buys and wears
T-shirts. What you will see in busy shops will be multiple jobs set up
on a single press at any given time. With a six-color press, you have
the potential of setting up six one-color jobs and have them ready to go
when the work day starts.
The platen is the board where you position the shirt for printing.
Often you will hear people call the platen a pallet, but the purist
will argue that the proper term is platen. Some presses, even multiple
color presses have only one platen for printing. More commonly, you will
see multiple platens, usually the same number of platens to match the
number of print heads on a press. These platens will move around the press independently from the movement of the screens around the press.
Platens move for two reasons. The first reason is to print a white underbase on a dark shirt, rotate the platen under a
flash cure unit, and then back to print the others colors on top of the
white underbase. We ideally need our platen to move so that we can properly and efficiently print dark T-shirts.
Can I print dark shirts with a single, non-moving platen? Yes, but I
will have to move the flash unit over the platen each time. It’s all a
matter of efficiency.
The second reason platens
move is so we can have someone else loading and unloading shirts while
we print. A helper loading and unloading will speed up the process.
During day-to-day printing though, most manual presses have a single
operator, and automatic presses will commonly have two operators, a
loader and an unloader.
I get the question often about purchasing
an all-heads-down press. That means you can print any screen on any
platen, all at the same time. If your press is not an all-heads-down
machine, you can only get one screen to lock down in place on one platen
at a time. The only time I’ve ever had need of an all-heads-down
machine has been in a classroom setting where a large number of students
are attempting to print sample garments. In nearly all shops,
only one operator is on a manual press at any give time, so
all-heads-down is an added expense that most of us would never use.
So, unless you’re opening a screen printing school, you can save your
money. Some manufacturers have ceased building all-heads-down manual
presses due to lack of interest in the marketplace. Of course, automatic
presses are all-heads-down devices, as all screens print
simultaneously.
Setting up the Press
Loading a
screen on the press is a simple operation for a single color. Each
additional color in the job complicates the process exponentially. No
matter how many colors/screens in the job, we want to lay out our
artwork in the center of the screen (from side to side) and slightly
higher on the screen (from bottom to top). This positioning allows for
ease of setting up on the press, and allowing room at the bottom of the
screen for a reservoir of ink, and room at the top for clearing the
print area with the squeegee.
The screen will lock into place in
the same place each time on our platen. If the artwork on our screen is
square with the platen, then it goes to reason that if our shirt is
placed on the platen straight, our print will be straight on the
finished garment, print after print.
Each screen is held in place
by either back clamps (across the bottom end of the screen), or side
clamps (on each side of the screen). Once locked down, the screen should
not move and will fall in the same place each time you lower it onto
the shirt and platen.
Setup the screen so there is about 1/8”
clearance between screen and platen. This is called printing “off
contact”. The only place the screen will physically touch the shirt will
be along the sharp edge of the squeegee blades as it passes across the
surface of the screen. Printing off contact will give us a clean, crisp
print on the garment.