The invention provides a method for making a printing form having a relief surface on a floor from a photosensitive element. The method involves generating a polymerization rate curve for the photosensitive element from a step exposure test by measuring a cure response, such as floor thickness or one or more relief image characteristic/s, of the element relative to an energy density of a source of actinic radiation. The method exposes a photosensitive element to the source of actinic radiation based on energy density that accounts for changes in intensity of lamps used for the source of actinic radiation.