The type and quality of the paint greatly affects how you clean a wall and how clean it will come. There are generally four types of paint finishes you might encounter:

Baked enamel (most appliance finishes), epoxy enamel and automotive paints
These paints are durable and stain-resistant. Dirt typically cannot penetrate the hard-finish. These types of surfaces can withstand scouring with mild abrasives and can also handle heavy-duty cleaners and de-greasers when necessary. With these finishes, you need to be most careful of scratching or dulling the finish by using harsh abrasives, steel wool, colored scrub pads and strong solvents.

General-purpose enamels
Most often found on interior walls, especially kitchen and bathroom walls, this type is stain-resistant and can handle moderate scrubbing. Do not use abrasive substances or colored scrub pads, as this finish can be scratched. Use a neutral cleaning solution and a white, nylon-backed scrub sponge. Only use heavy-duty cleaners or abrasive cleansers when you’re willing to take your chances on ruining the paint. If you have latex enamel paints, avoid leaving them wet for more than a minute or so. Oil-based enamels are more water-resistant. Keep in mind that gloss enamels are the most durable and washable, followed by semi-glosses and then satin finishes.

Latex flat
The most common household paint, flat latex is not as washable as enamels. Heavy-duty cleaners or hard scrubbing can remove the paint along with any dirt. Use mild detergents and gentle scrubbing, and don’t let any solution sit on the surface for more than a minute.

Exterior paints
These paints are typically oil-based or latex and should be scrubbed only with a mild detergent and then rinsed with a hose. Use a long-handled brush for hard-to-reach areas or stubborn spots. Some people like to use pressure washers on the outside of their homes, but like harsh chemicals, these can loosen the paint, so use with caution.