Additol VXW 6503 Cytec Surface Specialties Flow / Levelling agent Wetting agent/ Wet edge enhancer Coatings >> Waterborne Flow and substrate wetting agent for waterborne paint systems. Additol VXW 6503 is a levelling and substrate wetting agent based on a polyether modified polysiloxan for waterborne paint systems. Because of strong reduction in surface tension, it improves substrate wetting and levelling without foam stabilisation. Additol VXW 6503 does not increase surface slip, and does not influence recoatability. Flow and substrate wetting agent. Improves substrate wetting and levelling without foam stabilisation. Used for waterborne paint systems.