Zinsser Bulls-Eye? 1-2-3? gray primer is an all-purpose, high-performance, water-based primer for interior and exterior residential, commercial and industrial applications. Bulls-Eye? 1-2-3 gray primer has excellent stain blocking resistance, is fast dry and has excellent adhesion to glossy surfaces. Use Bulls-Eye? 1-2-3 gray primer with rich or dark topcoat colors to improve their hide and coverage. May be used under and over any oil or latex architectural paint. The dried film is mold and mildew resistant.