Formulation Cost Savings and Improved Coating Performance. ROPAQUE™ ULTRA E SLF is one of the most advanced polymeric opacifiers engineered to improve the efficiency of TiO2. It helps lower the consumption of TiO2, reduce the cost of all types of water-borne paints and improve paint performance. In addition to providing the most efficient dry-hiding properties, offers wide range benefits in interior and exterior paint formulations.