The Daler Rowney System 3 Screen Drawing Fluid 75ml is to use with System 3 colours, Printing medium & Screen Block. The Screen Drawing Fluid is applied with a brush direct to the screen to create a positive image. It can be applied neat or diluted with water. Non image areas are then blocked & once the screen block is dry, the drawn positive image is washed out in cold water to leave open-mesh ready for printing.