Spray painting is a process by which liquid paint is applied under pressure to an object. Spray painting may be carried out by hand or automatically. There are several methods used to atomise the paint for spraying. Conventional air compressor – compressed air is used to draw liquid paint out of the container and produce an air-paint mist from the nozzle of the spray-gun. Electrostatic spray painting – an electric pump drives the electrostatically charged liquid paint out of the nozzle which is then applied to the object which is earthed.