Zinsser Cover Stain Oil-Based Primer is an all-purpose oil-based primer designed for interior or exterior applications where an oil-based primer is desired. CoverStain provides excellent penetration and flexibility and has excellent adhesion and stain blocking properties. CoverStain has excellent adhesion to dense, glossy surfaces such as enamel paints and varnishes, paneling, laminates, and ceramic tile without the need for sanding or deglossing.