Exterior emulsion-based paints protect the subsurface by forming a sealed, flexible film. This coating film has low water vapour permeability and acts as an effective barrier against acidic gases (carbon dioxide, sulphur dioxide). Because of the reduced water absorption, the facade is protected for many years against damaging effects of water and driving rain. Exterior emulsion-based paints can be coloured with all types of weather-resistant organic and inorganic pigments. MEIAKI Cellulose is mainly used as rheological modifier and enhances the film formation of the binder.