Primer vs Undercoat: When Each Is Needed, How They Differ & The Mix-Up That Wastes Paint
Walk onto any site where a decorator has skipped a primer or substituted an undercoat in its place, and the result usually shows up within weeks. Flaking on new plaster. Tannin bleed through emulsion on knotty pine. A topcoat that won’t level because the substrate drank half of it. Getting primer vs undercoat wrong is



