Ligament-controlled effervesscent atomization (LCEA) was developed as a means of reducing effervescent atomizer air-to-liquid ratios by mass (ALR)from 2% to as low as 0.75%. This reduction in ALR offers an obvious advantage in numerous applications (e.g., combustion systems because of reduced parasitic losses or paint/coating sprays because of improved penetration into corners). Reduction of ALR is a necessity for consumer product sprays because of the limited quantity of atomizing air available in a prepressurized package. This study focused on passive control of entertainment by ligament-controlled effervescent atomizer sprays. Spray control was investigated by considering the entrainment-modifying effects of four exitorifice geometries having a common diameter of 0.38 mm but different indeterminate-origins-four-point crown, two-point crown, inclined, and stepped. Each geometry was tested at two liquid mass flow rates (0.5 and 0.6 g/s), four air-to-liquid ratios (0.75 less than or equal to ALR less than or equal to 2.0%), and four axial distances (67 less than or equal to x/d(0) less than or equal to 417). Data were acquired for a single bulk liquid-water. Both the atomizing gas and the entrainment gas were dried, high-pressure air. Steady entrainment rate and momentum rate data were used to calculate entrainment numbers, E, for sprays produced using each of the entrainment-modfying geometries. Results of this experimental investigation are summarized as follows: (1) Normalized entrainment rates (<(m)over dot>(e)/<(m)over dot>(l)) were found to scale linearly with normalized axial distance (x/d(0)) and to increase with increasing ALR for all exit-orifice geometries. (2) Entrainment numbers were found to increase with increasing ALR for all exitorifice geometries. (3) The four-point and two-point crowns were found to enhance entrainment by the sprays, whereas the inclined and stepped exits were found to suppress it.