Screen Press Printing: Looking At The Process

Screen printing also called silk screen print also calledfifteen minutes. After the screen has been exposed
serigraph was invented in the Far East around 2000it is taken to a wash out area usually a metal bathtub
years ago. No supplemented data on when or wherelike trough or large sink. The screen is set in the
exactly it originates, but originally used to make thetrough and sprayed with a garden hose. Rinsed with
screen printer's screen. A paper stencil was stichedwater, after a second the design will be visibly lighter
onto the screen to control the print area.in the emulsion. After a minute or so of rinsing the
Around a hundred years ago screen printing wasdesign area should be free of emulsion. Rinsing is
reinvented in the west and it has become a commoncontinued for another minute or so to wash away
method of printing on textiles. Most common, theemulsion scum that if allowed staying in the screen
custom t-shirts. The screens used for screen printingand dry will clog printing areas. The washed out
custom t shirts, are made with a mono filamentscreen is then allowed to dry.
mesh. Photopolymer emulsion is used to make theAfter it has dried the screen must be taped off. This
stencil. Thus, silk screen is coated with the liquidis usually done with masking tape. The areas around
emulsion, and allowed to dry and harden. Thethe edges not coated with emulsion are taped front
emulsion is light sensitive. The stencil is made in theand back. The screen printer applies tape liberally
"silk screen" by placing a positive of the print overover the frame and screen areas. The screen is then
the coated silk screen then exposing the screen to"pin holed". Sometimes imperfections in the screen
light. The areas of the screen shielded from the lightprinting process cause tiny "pin holes" in the emulsion
remain water soluble and can be washed out of thethat's why these must be taped over or blocked
screen. The light affects the emulsion in that oncewith emulsion or block out fluid. This is done on the
the dried emulsion has been exposed to light, waterbottom of the screen.
will not dissolve it. Take a look at the photograph toThe emulsion can be removed from the screens so
the left. In this case the positive for the screen printthat the screens can be reused. This is called
is hand drawn."reclaiming" the screen. After the print run the ink is
The availability of the screen printing products can bescraped out of the screen and mineral spirits or ink
purchased locally from screen printing process supplywash is used to clean the ink from the screen. All the
stores. An "emulsion cup" is used to coat the silkmasking tape is pulled off the screen and the screen
screens with emulsion. The emulsion cup is a troughis sprayed with "emulsion remover." This chemical is
like cup that holds the liquid emulsion and allows it toleft on the screen for 2 or 3 minutes and a high
be spread evenly across the screen. The screen ispressure sprayer or even a garden hose can be used
held vertically and the emulsion is spread fromto wash away the emulsion. After the emulsion has
bottom to top with one smooth motion. After thebeen removed the screen must be degreased. There
silkscreen has been coated with emulsion it will be leftare degreasing liquids available also ivory soap works
to dry. Ambient or soft light can expose the screenwell. The screen is scrubbed thoroughly on both sides
but it would take hours or days. Even so care shouldand then rinsed. It can now be dried and if kept clean
be taken that the silk screen is kept in a dark place.reused. The screens must always be clean and
To "burn" a screen, the positive must make tightdegreased and dry before they can be coated with
contact with the screen. A four inch thick foamemulsion.
rubber pad is placed under the screen with the glassThese procedures may sound very difficult but the
placed on top. Sunlight can now expose the silkapplication is totally easy. See and try the screen
screen. It can take anywhere from around two toprinting yourself!