The synthesis of structured latex particles involved the preparation of a slightly crosslinked poly(n-butyl acrylate) (PEA) seed and a poly(benzyl methacrylate-styrene) [P(BM-St)] shell. It was found that structured core-shell latex particles prepared by semicontinuous monomer addition yielded better coverage of the seed particles than those polymerized by batch and that poly(benzyl methacrylate) yielded better coverage than polystyrene (PS). Polymerizations in the presence and absence of a chain transfer agent indicated that the presence of isooctyl mercaptopropionate (IOMP) causes the second-stage monomer to polymerize as an isolated, single patch of shell material. In the absence of IOMP, smaller patches of shell material are spread throughout the PEA seed surface. The different morphologies obtained under different polymerization conditions were attributed to thermodynamic and kinetic factors such as polymer-polymer interfacial tensions and viscosity effects.