Abstract: An apparatus for developing an electrostatic latent image with liquid developing material. The apparatus includes a liquid developing material coating flow applicator for applying a substantially uniform coating of liquid developing material to a moving surface, wherein a housing, situated proximate to the moving surface, includes a fluid transport channel having a relatively narrow-width elongated outlet port for delivering a flow of liquid developing material to the moving surface, and an air flow channel having an elongated inlet aperture located adjacent the moving surface and immediately upstream from said outlet port for applying vacuum pressure to the flow of liquid developing material for varying the profile of the coating flow to provide variation of flow stability as well as thickness. A discussion of the effects of variations in the outlet port geometry, in particular, increasing the dimension between the downstream wall and the surface to be coated, has also been provided.