Abstract: A screen printing assembly attachable to a screen frame supporting a screen having a pattern. A support frame, which comprises a flat aluminum extrusion, is positionable adjacent and attachable to the screen frame. A squeegee assembly is movable relative to the support frame and positionable generally on the screen to press ink through the screen. A sealed chamber is connected to the bottom of the support frame and positionable generally adjacent the screen. The squeegee assembly presses the ink through the screen within this sealed chamber. The sealed chamber safety contains the printing ink solvents which are deposited in it. A flexible plastic sheet forms the upper surface of the sealed chamber. This sheet, which can have ultra-violet properties, rolls at its opposite ends about rod assemblies. The sheet is attached to the squeegee assembly and moves with it between these rod assemblies. Tension springs mounted in the rod assemblies keep the sheet taut.