Alkenyl succinic anhydride is an effective sizing agent involved in alkaline papermaking. There are many factors in the alkaline papermaking system which effect the retention of the sizing agent. This study reviews factors which influence sizing and the effects of shear and alum addition on the retention of ASA. The Dynamic Drainage Jar was employed to subject four levels of shear on the system and Hercules size determinations were conducted as a measure of retention. Alum is necessary in the system to provide proper retention of the ASA. Retention of ASA with alum present was found to increase with increasing shear until a point of 1000 RPM was reached. After this point, retention decreased sharply