A thermal printhead includes a substrate, a nonconductive coating over the substrate, a number of heating elements disposed on the substrate, and one or more resistors at least partially disposed within the nonconductive coating. The heating elements cause thermochromic media to selectively darken in accordance with selective activation of the heating elements as the media moves in relation to the thermal printhead, to print a desired image on the media. The nonconductive coating protects the heating elements and wears away with usage of the printhead. The media comes into contact with the nonconductive coating during printing of the desired image on the media. The resistors indicate wear of the thermal printhead, and have electrical resistances that increase as the resistors are worn away in accordance with wearing away of the nonconductive coating.