Paint that fails to resist absorption of dirt and stains suffers from poor stain resistance.
What Causes It?
Porosity can lead to this condition. So, using of lower quality paint that is porous in nature or applying paint to an unprimed substrate can both lead to poor stain resistance.
How to Solve It
Higher quality latex paints contain more binder, which helps prevent stains from penetrating the painted surface, allowing for easy removal. Priming new surfaces provides maximum film thickness of a premium top coat, in turn providing very good stain resistance and removability.
Note: images provided by The Rohm & Hass Paint Quality Institute.