A drop generator operable to selectively form a drop having a first size and a drop having a second size from liquid emitted through a nozzle associated with the drop generator. The drop having the first size and the drop having the second size travel along a drop trajectory with the first size being larger than the second size when compared to each other. Each of the drops has a drop velocity. A gas flow deflection system includes a gas flow that is directed at a deflection zone that comprises at least a portion of the drop trajectory. The gas flow in the deflection zone includes a velocity vector having a parallel velocity component and a perpendicular velocity component with the parallel velocity component and the perpendicular velocity component being defined relative to the drop trajectory.