Ice protection systems for aircraft, and methods of their manufacture, where the ice protection system includes a metallic substance applied to a nonconductive substructure of the external skin portion at a leading edge of an aircraft, an electrical power source, and a conductor circuit electrically connecting the power source across the metallic substance. In particular, the metallic substance may be applied to a nonconductive substructure on an annular inlet surface of an aircraft nacelle lip skin, and a power source can be electrically connected across the metallic substance.