Field emission gun SEM (FEG-SEM) data is described for a number of commercial 6xxx series ingots after various homogenization type thermal treatments. The alloys include both rolled and extruded products and contain a range of manganese and chromium contents. The particle characterization results are used to fit a model for dispersoid evolution during thermal processing. The model follows dispersoid changes via nucleation, growth/dissolution and coarsening, and is comprised of evolutionary equations for number density and volume fraction. The dispersoid phase is assumed to be a substitutional solid solution of iron, manganese and chromium in A112, which allows for a range of manganese and chromium contents to be covered. The fitted model takes as inputs alloy composition and arbitrary thermal history, and outputs dispersoid and solute quantities.