A radiation dosimeter for measuring the dose of radiation applied during radiation therapy includes a substrate, a phosphor containing layer including a stimulable phosphor and a binder on a side of the substrate, the weight ratio of the binder to the phosphor in the phosphor containing layer is 10 or higher, a colorant, and optionally a layer in contact with the phosphor containing layer. The colorant provides a total light absorbance of the layers applied on the side of the substrate containing the phosphor containing layer of at least 0.04 at the stimulation wavelengths of the stimulable phosphor.
