What is the purpose of primer?

• A. To promote adhesion and protect the surface
• B. To provide gloss
• C. To fill large scratches
• D. To color the surface

Answer: (A)

Primer's job is to provide a good bond between the surface and the finish while protecting the material underneath. It creates a uniform, sealed base that helps the topcoat adhere reliably, which is essential for long-lasting paint adhesion. On metal, it also acts as a barrier to moisture and corrosion, and it seals porous areas or repaired spots so the color coat goes on evenly. While some primers can be tinted to help color matching, their main purpose is not to add gloss or color. Gloss comes from the topcoat and clear coats, and filling large scratches is the job of body filler (or specialized filler primers) rather than standard primer.