Porous sintered anode bodies for capacitors formed from valve metals are treated by electrolysis to form a dielectric layer and coated with cathode layers. When standard parallelpiped shapes are used, cathode coverage at the edges and corners is non-uniform and failures occur at those locations. Rectangular prisms, obround prisms and cylindrical prisms are formed with transition surfaces at edges and corners, such as chamfers and curves, to enhance cathode layer uniformity. The transition surface greatly enhances the application of polymer slurries.