a spray gun operable by low pressure high volume air is described . the spray gun comprises an air cap formed with a central spraying aperture and a fluid nozzle projecting toward the spraying aperture , the profile of the nozzle is a plain frustum of a core terminating at a small front face bounding an orifice through which fluid is discharged . the arrangement being such that in operation a flow of atomizing air that emerges through a gap between the nozzle and the air cap attaches to the nozzle and to an emergent fluid jet which assumes a conical form that is a continuation of the nozzle surface and changes to a parallel jet before it breaks up into atomized droplets .