Disclosed are conductive ink compositions that include at least one monomer containing exactly one ethylenically unsaturated group, one or more thermoplastic polymers, one or more free radical initiators, and conductive particles. The liquid bituminous material is atomized by mixing it with a pressurized gas, such as compressed air, forming a mist comprising droplets of bituminous material having a diameter between 20 microns and 50 microns. The combustor is formed with a purging air flow passage that injects purging air in the purging air space to a downstream side relative to the base plate. The identifier portion may comprise text, graphics, raised lettering or symbols, color coding, aroma coding, or a combination thereof.