Testing Dried Paint on a Wall

• 1). Visit your local hardware store and buy a small can of methylated spirits, also known as denatured alcohol. It should be in a metal can sealed with a safety lid.
  
  
• 2). Dip the rag into the spirits so a piece of the rag is saturated. It is helpful to use a rag that is an opposite tone of the paint you are checking, so if any paint comes off you will see it immediately.
  
  
• 3). Hold the rag against the wall you want to test for about 30 seconds.
  
  
• 4). Move the rag away from the wall. If the paint appears soft and begins coming off the wall, then it is water-based paint. If the paint does not move, it is oil-based.