An airbrush is a small, air-operated tool that sprays tanning solution by a process of nebulization. Airbrush machines are used to apply special tanning solution as a form of sunless tanning that simulates the appearance of a natural sun tan. It is safer and healthier alternative to the damaging effects of long term exposure to the sun.
An airbrush machine works by passing a stream of fast moving (compressed) air through a venturi, which creates a local reduction in air pressure (suction) that allows tanning solution to be pulled from an interconnected reservoir at normal atmospheric pressure. The high velocity and low pressure of the air atomizes the spray tan solution into very tiny droplets as it blows past a very fine solution-metering component. The tanning solution is thus carried onto the skin. The operator controls the amount of solution using a variable trigger which opens more or less a very fine, tapered needle that acts as the control element of the solution-metering component. An extremely fine degree of atomization is what allows a spray tan artist to create such smooth contours and blending effects using the airbrush machine.