Unlike the case of air atomisation, airless atomisation technology atomises the material using the pressure of the material alone, i.e. without the use of any air. An electric, pneumatic or petrol-driven pump pressurises the material and forces a defined quantity of material through a nozzle aperture at up to 25 MPa. During this process, the material is diffused into a finely atomised spray jet. Although airless technology is particularly suitable for the application of emulsions, this spray process is also often used for painting jobs on building sites. WAGNER marking units also use airless spraying technology.