Speedball Screen Filler can be used in conjunction with Speedball Drawing Fluid, or for simply blocking out areas of screen mesh that you don't want to print through.
Use the drawing fliud to paint your design onto the screen. The painted areas will form the printed areas of your design. Once the Drawing Fluid is dry apply Speedball screen filler over the top. This is best done with a squeegee. Then with cold water, wash out the drawing fluid. You will then have areas of open mesh through which you can screen print.