To clean flat paint walls effectively, use gentle, non-abrasive methods to avoid dulling or removing the finish. Here’s a straightforward, reliable approach with options for common stains and general maintenance. Direct answer

• Start with dusting: Use a microfiber cloth or a soft duster to remove loose dirt and cobwebs from the wall surface before washing. This minimizes streaks and scratch risk.
• Basic washing (safe for most flat finishes): Mix a small amount of mild dish soap with warm water. Dampen a soft sponge or microfiber cloth in the solution, wring well, and gently wipe the wall in sections. Rinse the sponge frequently and use clean water to rinse the wall if needed. Dry with a clean towel or allow to air dry. This works for everyday dirt and light smudges.
• For tougher spots:
  • Use a diluted detergent solution (about 1 tablespoon of detergent to 1 gallon of water) and gently scrub the area with a damp sponge. Rinse with a clean, damp cloth and dry.
  • For pencil marks, crayon, or scuffs, you can try a mild eraser or a small amount of white vinegar on a damp cloth, then rinse and dry. Test on an inconspicuous spot first.
• For stubborn stains: If general cleaning doesn’t remove the stain, use a dedicated, non-abrasive wall cleaner or a foam cleaner following the product’s directions, testing first on a hidden area.
• Repaint as a last resort: If staining or finish wear persists, consider touching up with matching touch-up paint, or repaint the affected wall with a sheen that’s easier to clean (eggshell) if the flat finish is too delicate.

Tips to protect flat paint

• Always test cleaners on a small, inconspicuous area first to ensure there’s no discoloration or finish damage.
• Avoid abrasive sponges, steel wool, or harsh chemicals like bleach directly on flat paint, as they can dull or remove the finish.
• Dust walls regularly to reduce the frequency of washing needed.
• For high-traffic areas, you might prefer a slightly more durable finish (such as eggshell or satin) in future repaint projects for easier cleaning.

If you’d like, share the type of stain (crayon, ink, oil, water-based spill) and a photo of the wall, and I can tailor cleaner suggestions and a step-by- step plan.