One of the most important things to be aware of is that paint is formulated for either interior use or exterior use, and they have different properties: Interior paint is formulated for: Scrubbability and stain resistance; Good hiding ability; Splatter resistance; Easy touch-up. Exterior paint is formulated for: Color retention; Resistance to fading; Flexibility to withstand expansion and contraction due to weather; To provide a mildew resistant coating; Resistance to tannin bleed. Don’t think that you should use exterior paints indoors on the assumption that it is “tougher”. In fact, some of the highest-grade exterior paints can be worse to use indoors than a lower-quality interior paint.