What is the main function of primer-sealers?

Primer-sealers primarily serve the function of covering existing finishes. They are designed to create a uniform base for subsequent paint layers, improving adhesion and allowing the topcoat to apply smoothly over varying surfaces.

When a surface is previously painted or has imperfections, a primer-sealer effectively acts as a barrier, ensuring that the new paint applies evenly and adheres correctly. This is important for preventing issues like peeling, blistering, and inconsistent sheen levels in the final finish. In addition to providing good coverage, primer-sealers can seal in stains or other contaminants, preventing them from bleeding through the new paint layer.

Adding color or acting as a decorative finish are not the primary roles of primer-sealers; instead, their focus is on preparation and enhancement of the surface's readiness for paint application. Additionally, enhancing surface texture isn’t a function attributed to primer-sealers; they aim for a smooth surface to facilitate the application of topcoats.