How many coats of semi-gloss paint?

For semi-gloss paint, you typically need two coats over a properly primed surface for best results, though the exact number depends on surface condition, color change, and application method. Primer counts as the first preparatory layer, but it is not a finish coat. After primer, one coat of semi-gloss often looks patchy, uneven, or slightly translucent, especially when covering a darker color with a lighter one or when painting bare wood or drywall. Two finish coats provide full, even color coverage, uniform sheen, proper film thickness for durability, washability, and moisture resistance, and a smoother, more professional appearance. If you are painting over a similar color in good condition that is already semi-gloss and you have cleaned and scuff-sanded it well, you might get away with one coat, but two coats will still look richer and last longer. For trim, doors, and cabinets where durability is critical and imperfections show easily, two coats is the industry standard, with light sanding with 220 grit sandpaper between coats to remove dust nibs and improve adhesion. Always follow the manufacturer's recommended drying time between coats.