Zinsser® ShieldZ® Universal Wallcovering Primer is a one step, mildew-resistant, high-hiding primer for use on all surfaces, with all adhesives, and under or over all wallcoverings. ShieldZ Universal provides excellent adhesion and makes wallcovering removal easy later. Designed for use on existing wallcovering, paneling and gloss surfaces. Use on regular paint, porous flat paint or unprimed drywall.