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close this book Tools for teaching - A visual aids workshop, and instruction manual for health educators
close this folder Session 7. Project $3: Design/project #4: Planning 7.0
close this folder Handout 7.7.1 - A silkscreen manual (Supplementary learning materials)
View the document A. Silkscreen frame construction
View the document B. Squeegee construction
View the document C. Silkscreen assembly
View the document D. Silkscreen art preparation (cut stencil method)
View the document E. Cutting the stencil
View the document F. Adhering the stencil
View the document G. Silkscreen inks & solvents
View the document H. Printing
View the document I. Silkscreen clean-up

G. Silkscreen inks & solvents

1) The secret to successful silkscreen printing is in knowing the compatibilities/incompatibilities of stencils, inks, and solvents.

• The ink must not dissolve the stencil because the image will be destroyed.

• The stencil must have a solvent or the screen will be useless for further printings.

 

GUIDELINE FOR STENCIL/INK/SOLVENT COMBINATIONS

 

Ink solvent

Paper stencil

Water soluble stencil

Lacquer soluble stencil

         
         
         

Water-base ink

water

limited # of copies

no

yes

Oil-base ink

turpentine

yes

yes

yes

Stencil solvent

- - -

none needed

warm water

lacquer thinner

 

2) As noted in the above chart, there are two types of silkscreen ink: water-base ink and oil-base ink. Both types may be purchased commercially, however the most commonly used (and thus most widely available) commercial silkscreen ink in the Philippines is a water-base textile ink. This ink may be used on paper as well as textiles provided the paper stock is somewhat porous, i.e. has not been coated with a hard, slick finish. The type of inexpensive paper recommended for the visual aids workshop accepts this water-base textile ink without any problem.

3) If you prefer to make your own silkscreen ink, both oil-base and water-base inks may be homemade according to the following directions:

RECIPE #1 (oil-base ink)

Thicken ordinary oil-base paint with wood-filler, talc, or powdered clay to a consistency halfway between heavy cream and pudding (or champarado without any lumps).

.

RECIPE #2 (water-base ink)

non-instant starch 120 ml. (½ cup)

boiling water 350 ml. (1½ cups)

soap flakes 120 ml. (½ cup)

coloring (tempera paint powder, ink, or food coloring)

Mix starch with enough cold water to make a smooth paste. Add boiling water. Cool until glossy. Stir in soap flakes while mixture is still warm. After the mixture has cooled, add coloring.

 

RECIPE #3 (water-base ink)

cornstarch 60 ml. (¼ cup)

boiling water 460 ml. (2 cups)

soap flakes 30 ml. (1/8 cup)

coloring (tempera paint powder, ink, or food coloring)

Dissolve cornstarch in a small amount of cold water.

Mix two or three tablespoons of boiling water, one spoonful at a time, into the cornstarch mixture.

Stir well to get rid of all the lumps. Pour the cornstarch mixture very slowly into remaining boiling water, stirring constantly. When mixture boils, reduce heat and continue to stir until thickened. Add soap flakes while still warm. Cool and add coloring.

 

RECIPE #4 (water-base ink)

cornstarch 120 ml. (½ cup)

gelatin (unflavored) 1 envelope or 15 ml.

soap flakes 120 ml. (½ cup)

water 700 ml. (3 cups)

coloring (tempera paint powder, ink, or food coloring)

Dissolve cornstarch in 170 ml. (3/4 cup) cold water.

Dissolve gelatin in 60 ml (% cup) cold water. Bring 460 ml. (2 cups) of water to a boil. Stirring constantly, slowly pour in cornstarch mixture followed by dissolved gelatin. When mixture begins to boil again, reduce heat and continue to stir until thickened. Cool mixture, then add soap flakes and coloring.

NOTE: One or two teaspoons of glycerine added to the water-base inks will make them smoother and easier to use. All four of these homemade inks will last for several months if stored in jars with tight-fitting lids.

4) Standard black mimeograph ink may also be used to print handwritten or drawn gestescript stencils or typewritten stencils. Standard mimeograph ink is an oil-base ink, soluble in turpentine.

5) A word about color -

Bright, bold colors are most effective for. visual aids and display posters. Try to avoid pastels and muted shades. Buy or mix RED, YELLOW, BLUE, GREEN, and BLACK. From these five colors you can also make ORANGE (from RED and YELLOW), PURPLE (from RED and BLUE), and BROWN (from RED and GREEN, or PURPLE and YELLOW).