a drop on demand printer is provided having : an ink ejection location for ejecting ink droplets , the ejection location having an associated ejection electrode for causing electrostatic ejection of the droplets from the ejection location ; an intermediate electrode spaced from the ejection location , and in use disposed between the ejection location and a substrate onto which the droplets are printed in use ; wherein either the ejection electrode or the intermediate electrode is coated with a film , the film being formed from a blend of a polymer insulating host and a conducting polymer dopant .