The screen has been exposed, and the positive removed. Now we have to
wash out the screen. Most people believe water pressure is required. Wrong. That
is not how emulsion and capillary film work.
After the positive has been removed, feel the image. It is smooth and you cannot
see the image. Then stand the screen vertically in the wash out booth
or sink and simply run water down both sides of the screen. No pressure. The
image becomes apparent. Now lay the screen in a horizontal position with
the print side up and ink side facing down. Lay a paper towel over the
image area, and spray water on the paper towel. The wet towel holds
the water on the image. After two minutes, peel the paper towel off,
and now the image is very visible. That is because the image is swollen
with water. Feel the image. It feels like grease. Feel the
exposed areas of the screen, and they feel wet, but not like grease.
Now spray water at the image, but just using the water pressure in the sink. A
lot of water pressure is not necessary and will damage the soft screen. The
emulsion or stencil from capillary film is weak from the expansion caused by
the absorption of water, and will wash out. If using thick films for
3-D inks, the water only absorbs to a certain depth and therefore only washes
out to that depth. The image looks like an etching. More water
will have to be put in this partially washed out area and allowed to stand
again for two minutes to absorb causing the stencil to swell.
Additional information is available in these articles:
“How to Build Thick Stencils”
“Applying & Laminating Capillary Film”