The invention relates to conductive heaters, and has its objective to provide a material that exhibits a uniform heating effect over the full area of the heater, relatively free from hot and cold spots, a further objective being to maintain the heater pliable. These objectives are met by a conductive material comprising finely divided carbon particles uniformly dispersed in an elastomeric carrier there being carbon particle levels of 20% to 75% by dry weight to carrier levels. Preferably, the carrier is an elastomeric polymer. A further aspect of the invention is a method of forming a compound for an electrically conductive heater comprising stirring fine carbon particles into a polymer base containing an anti-adsorption compound, to achieve carbon particles to polymer levels of 20% by dry weight to 75% by dry weight, and subjecting mixture to high speed stirring for a pre-determined period of time, with the maintenance of the mixture below a predetermined level, to grind the carbon particles to a predetermined final fineness.