A product (20, 21, 41, 60) comprised of a three-dimensional network of material is coated with a particulate support. The coating may be applied by an electrophoretic coating procedure to apply a particulate coating on the surface or into the interior portions of such three-dimensional network of material (20, 21, 41, 60). In one embodiment, the particles are a catalyst or a catalyst precursor or a catalyst support to thereby provide a catalyst structure in which catalyst may be supported as a coating in the interior and on the exterior of a three-dimensional network of material (20, 21, 41, 60) having a high void volume. Edge effects may be reduced by control or disruption of field lines during the coating. In addition, larger particles may be electrophoretically coated onto a product (20, 21, 41, 60) by the use of smaller particles which function as a 'glue'.