Screen printmakers apply a blocker to a silk screen stretched across a rectangular frame. Once the blocker dries, the screen printer wipes ink horizontally across the surface of the screen with a squeegee. The squeegee pushes a small amount of ink through the silk and onto the destination medium below. The printmaker removes the screen and waits for the print to dry. The total number of colors in the source art determines the separation process, the number of screens and how many applications of ink the printmaker will need.
Making monotone prints requires only one color of ink and therefore only one screen. The printmaker applies the ink to the destination medium in one pass, then waits for it to dry. When creating the original design, the printmaker takes into account that the hue of the destination medium will fill any negative space in the screen printed version.
Printmakers achieve full color by combining multiple applications of single ink of different hues. They may use software, photo emulsion or hand-designed overlays to split an image into multiple monotone screens, then use each screen to apply a different ink color. Techniques for making color separations include process, simulated process, and spot color.
In this technique, the printmaker applies photo emulsion to one or more screens. Then, she shines light through the original art or color separations to transfer the design to the light sensitive emulsion. She develops the emulsion using photochemicals, then uses it to apply ink to the destination medium. Printmakers with a background in painting or illustration may find the photo emulsion technique to be more scientific than creative.
In this technique, the printmaker pre-visualizes a design and paints it in negative with blocker on one or several silk screens (depending on the number of colors). Once the screens dry, the printmaker uses them to apply ink to the destination medium. Some printmakers enjoy the spontaneity, looseness and impermanence of hand painting screens. The hand-painted technique lacks the exactitude of the photo emulsion technique. Color registration and alignment may present problems to the inexperienced printmaker.