Political Signs - Real Estate
Signs - Lawn Signs - Yard Signs - Bandit Signs (800)
High Quality Screen Printed Signs: The Screen Printing Process
We take the artwork you send us or that we create for
you and create the traps necessary for proper color
registration then we separate the individual colors
and send them to the art department for printing.
Print the Film
The art department takes the file we send them and
prints the individual color separations to film on one
of our Roland FJ-500 large format inkjet printers.
Coat the screen
We start with a clean screen. Our screens are aluminum
frames with 305 tpi mesh stretched over them. The mesh
is similar to panty hose, except it's a much more expensive
and there are many more threads per inch. As I said,
our mesh is 305 tpi which means there are 305 threads
per square inch in each direction. That's a bunch of
This clean screen is coated on both sides with a UV
sensitive emulsion. Then the screen is placed
in our dark room to prevent it from being exposed to
UV light. Once the emulsion is dry it rinse
out with plain water until it is exposed to intense
UV light. Once the emulsion has been exposed to
a UV light source it becomes very tough and requires
a special chemical to remove it from the screen mesh.
Burn the screen
The film the art department printed is placed in the
proper location on the screen and taped into place.
The coated screens with the artwork are then place
into a large vacuum frame which 'sucks' the screen and
the artwork down flat against the front glass of the
frame. This is to prevent any light from getting
under the edge of the film. Light getting under the
film would cause an under burn. This would prevent some
areas of the screen from washing out during the rinse.
Then we turn on our 5kw light source. This
exposes the sections of the screen that are not covered
by the black film to be exposed to intense UV light
which makes the emulsion very tough. The areas of the
screen under the black part of film do not receive any
UV light, so they will still rinse out with plain water.
Rinse out the screen
Now we take the exposed screens to the wash out booth
to rinse out emulsion that was not hit with UV light.
You can see in the photos to the right how the image
begins to appear as the water rinses over the screen.
This produces a screen that matches the film we taped
on the screen.
Dry the screen
Next the screens are set outside is the sun for drying
and post curing. This post curing is done to ensure
the emulsion is completely cured to prevent cross-linking
of the ink and emulsion during the screen printing process.
If the emulsion is under cured and cross-linking occurs
it makes it difficult to clean out the screen mesh.
Pinhole and tape the screen
Next we inspect the screen very closely for minor holes
in the emulsion. Any pinholes or imperfections in the
screen are then covered with screen blocker. If you
click on the image to the right and look closely at
the more detailed picture you will see little green
spots on the screen. These green spots are the screen
block we use to block out the pinholes.
Then the edges of the screen are taped to prevent any
ink from running out on to the screen printing press.
Setup the press
The taped and pinholed screen is then loaded into the
press and the corrugated sign board is lined up to screen.
Once the sign board has been lined up we place plastic
stops at the back and the side of the sign board.
Print the signs
Now after 3 hours of work and waiting we can actually
print the first sign. The ink is poured into the screen
and the printing of your political signs begins.
Cure the signs
Once the corrugated sign has been printed we place
on the UV reactors' belt. The sign runs under a 18,000
watt light bulb and 'drys' instantly. These political
signs are ready to stack to the ceiling after they fall
off the belt. The term 'dry' is a bit misleading,
the correct term would be 'cure'. The UV inks are cured
solely by the 18,000 watts of light.