Abstract: A binder system useful in formulating coatings for glass, metal, wood and especially light diffusive coatings for glass light bulb envelopes is disclosed. Excellent coatings can be formed using a binder system comprising dispersible colloidal particles of alumina and finely divided, precipitated silica. When a stable dispersion of these two materials is combined properly with a pigment and/or filler system and then dried upon a glass, metal or wood surface, a tough, continuous, tightly adhering coating is formed. By using the correct pigments, a light diffusive coating for light bulb envelopes can be formed.