In this paper, a semiclassical approach is used to describe a kind of black-body which we will call
a matte black-body. Although the frequency energy density of a black-body is deduced using a
semiclassical method which includes the electromagnetic reaction force and the quantization of the
energy, a phenomenological damping force, as in the explanation of the anomalous dispersion of some
fluids, is considered in order to obtain the corresponding frequency energy density of the matte
black-body. The concept of emissivity is incorporated into the new body in order to explain the
experimental data of the radiation measured in the Earth’s atmosphere. The purpose of this article
consists of showing students the applicability of semiclassical approaches in obtaining physical
results.