The next step is to paint screen filler around your drawing (any paint brush should work). The screen filler will prevent ink from penetrating the polyester screen so essentially you are creating a stencil. It is obviously important that you figure out your positive and negative space before you start painting the filler. The screen filler has a red hue to it and has the consistency of acrylic paint. The filler will take a little while to dry so set it aside for an hour or so. If the screen feels dry when you touch it then it should be fine. Hold the screen up to the light to check for pin holes that ink might escape through. If you find any then simply spot check those areas with a little extra screen filler. Now you are ready to print.