Exposing a Screen
3730 E. Southern Avenue, Phoenix, AZ 85040 USA
800-778-8779
Workhorseproducts.com
8
Step 3:
The screen needs to be dried in a dark location. Dry the
screen in a horizontal position with the outside print side
facing down. This positioning is essential to aid the draw-
ing emulsion to create a flat and smooth surface. A fan
can be used to circulate the air around the screen to de-
crease the drying time. The normal drying time for a
properly coated screen can be anywhere from 30 –60
minutes. However, areas that have moisture in the air
will take exceedingly longer.
Step 4:
There is no standard exposure time because of all of the variables
involved. Use an exposure calculator to properly determine the
correct exposure time. Most emulsion manufactures have their
own exposure calculator, but they all relatively function in the
same manner.
Exposure calculators are film positives that have various degrees
of detailed lines that are covered with different factors. The pur-
pose is to expose the calculator onto a screen as a starting time and
each filter will have a factor number. After the screen is washed out,
observe which image is the hardest while containing the most detail
and multiply the factory number by the starting exposure time to get
the correct exposure time.
A Workhorse SD-10 drying cabinet will drastically speed up the drying process and eliminate the danger of
dust, which will guarantee high quality screens and increase production speed.
For example, a screen is exposed for one minute with the calculator and the best image washed
out has a filter factor of .5 , so 1:00 x .5 = 30 seconds. To guarantee the best screens, test every screen that
has a different variable like: different mesh count, different emulsion brand, and different coating technique.
A dual cure emulsion will need a starting point of at least two minutes with an exposing calculator.
A basic diazo emulsion will need a starting point of at least five minutes with an exposing calculator.
It’s best to test for each season change. The seasons influence temperature, humidity and moisture that will
affect the exposing of a screen.
