An airless paint spreader is a high pressure paint sprayer consists of an electronic hydraulic pump which spreads paint quickly on a wall or any other surfaces. The term airless means paint is applied under very high pressure, generally 1500 to 1300 PSI. An airless paint sprayer is used for big projects because it could spread paint efficiently in minutes. Rating of airless paint sprayer is based on GPM (gallons per minute), GPM explains the working of an airless paint spreader that how efficiently it paints and how much time it takes. PSI (pounds per square inch) is a term which measures the pressure of paint sprayer. It is very important to know before purchasing an airless paint sprayer for a particular job that how many gallons a person wants to paint, how much area is required to paint, what electric sources are available, required time, life of an airless paint sprayer and its market price, is it affordable or not? An airless paint sprayer comes in two sorts of pumps listed as diaphragm and piston. A diaphragm pump causes the 0 fluctuation in pressure while piston pumps causes more fluctuations. Diaphragms pumps are more efficient, quick and cheap in price than piston pumps. There are many things that you can do to get one. Some are at garage sales, others can be bought online.