The nucleation of polymer particles in the miniemulsion polymerization of vinyl acetate/VeoVa10 (VAc/VeoVa10) stabilized with PVOH was studied. The effect of costabilizer type, PVOH concentration, and type (thermal water-soluble and oilsoluble; and redox water-soluble) and concentration of initiator on the extent of droplet nucleation were studied. Droplet nucleation was maximized by improving miniemulsion stability and using efficient initiators. These high solids dispersions could not be obtained by using a conventional batch emulsion polymerization. (C) 2008 Wiley Periodicals, Inc.