What is a guide coat?

• A. A heavy paint layer used for hiding imperfections
• B. A masking tape technique
• C. A light coating used to identify surface imperfections
• D. A primer additive for adhesion

Answer: (C)

A guide coat is a light, contrasting coating applied to a panel during prep to reveal surface flaws. By laying down a thin color, high spots are removed more quickly when you sand, while low spots hold the coat longer, making low areas, scratches, and contour irregularities easy to see. This visual feedback lets you evaluate flatness and feather edges before priming, helping you achieve a smooth, uniform surface. It’s a temporary aid, not a heavy paint layer to hide flaws, not a masking technique, and not a primer additive for adhesion. Once you sand until the guide coat is evenly removed, the surface is ready for priming.