Divide your A4-sized piece of acetate into four sections. Draw a different pattern in each section. For example, you could draw polka dots in one section, flowers in the second section, triangles in the third and leaves in the fourth. If you are not confident that you can draw the designs, select patterns and trace them on each section of the acetate.
Cover the area under which you are working with thick cardboard. Cut out the parts of each pattern you want to print. For example, when making a polka dot pattern, you would cut out the dots so that they would print. This creates a mixed-pattern stencil.
Place a piece of A4-sized paper on the work surface. Place the mixed-pattern stencil directly on top of the paper. Line up the edges of the paper and the acetate stencil.
Put the screen down on top of the stencil. Use masking tape to mask off any areas on the underside of the screen that are not covered by the acetate stencil. Place printing ink on the top of the screen. Pull the ink down the screen with a squeegee held at a 45-degree angle.
Pull up the screen from left to right. The mixed patterns will be printed on paper.
Repeat steps 3-5 to for as many mixed pattern prints as desired. Once you have finished printing, scrape any excess ink off the screen and place it back in the pot. Wash the stencil, screen and squeegee in water to remove the ink.