Incandescent source of visible radiations comprises a refractory support member having a thin, refractory material layer thereover, with both the support and the thin layer adapted to be heated to high temperatures. The material comprising the thin layer is highly absorptive for visible radiations and thus is a correspondingly good emitter for such visible radiations, and the material comprising the thin layer is highly transmissive for infrared radiations and a correspondingly poor emitter for such infrared radiations. Minute optical discontinuities in the thin layer act to scatter infrared radiations and the infrared radiations which are generated in the support member are scattered back to the support member in order to contribute to the heating of same. Visible radiations, in contrast, are absorbed and emitted by the thin layer so that this layer is a very selective radiator. In this manner, infrared radiations generated in the support member are selectively scattered to contribute to the heating of the support member and thus the generation of more visible radiations which the thin layer emits.