| Tools for teaching - A visual aids workshop, and instruction manual for health educators |
|Session 7. Project $3: Design/project #4: Planning 7.0|
|Handout 7.7.1 - A silkscreen manual (Supplementary learning materials)|
Because blue film is a lacquer-base material, it is soluble in lacquer thinner. The secret to adhering the film to the silkscreen is in using just enough lacquer thinner to soften the film sufficiently so it will stick to the screen, yet not so much that the stencil dissolves altogether, destroying the image.
Blue film stencils, properly adhered to the screen, are reusable for multiple printings. Beginners should practice with a small piece of film in an empty corner of the screen.
Lacquer thinner will remove nail polish.
Wear rubber gloves to protect your manicure.
1) Set the silkscreen attached to its baseboard on the work table.
2) The stencil should be adhered to the bottom side of the screen. Lift the frame and position the stencil, film side up, on the baseboard. Some people find it easier to bond the stencil to the screen if there is a "cushion" of newspaper to work against. Try placing several layers of newsprint on the baseboard before positioning the stencil.
3) Now, lower the frame and adjust the stencil so that it appears in proper printing position on the screen.
4) Moisten a rag with lacquer thinner and, using firm pressure in small, circular motions, dampen the silk as you press it on to the stencil. Alternately press the dampened silk firmly on to the stencil with a dry cloth. Work on only a small area at a time, beginning in the center and slowly working outward until the complete screen has been dampened and pressed into the blue film. The whole stencil should adhere to the screen when the frame is lifted. Two or three persons can work at this task simultaneously.
5) Allow the screen to dry for a few minutes. Then, very gently, carefully, and slowly, peel the paper backing away from the bottom of the screen. If you should notice that the film is also pulling away from the screen, lower the frame again and use a little more lacquer thinner on the rag to readhere the stencil.
6) Once the stencil is adhered to the screen and the paper backing has been removed and discarded, check for any open areas between the outer edge of the stencil and the frame. Seal these with gloss varnish so that the ink will not be pushed through these spots when you print. You can also touch up the edges of the images, if necessary, with a small brush dipped in the gloss varnish. Clean the brush in lacquer thinner immediately after use.
7) Set the silkscreen aside with the frame propped open so that the silk will dry thoroughly. The silkscreen cannot be used for printing unless the stencil is properly adhered and the screen is completely dry to the touch. Allow at least 30 to 45 minutes drying time.
8) Repeat this procedure, adhering each of your stencils to a different screen.