AbstractThe absorption of optical radiation by an (incidentally) fluorescent absorbing material was studied in the presence of substantial amounts of scattering. If surface‐reflection corrections are neglected, the apparent absorptance of the system is “enhanced” in the presence of scattering. However, in this case attempts to use the Kubelka‐Munk turbid‐medium theory to compute the results do not lead to an accurate and adequate explanation. If surface‐reflection corrections are applied, all observed phenomena can be explained, but a negative enhancement is predicted. A new Saunderson‐type correction equation for surface reflection of the diffuse internal transmittance is derived and applied. Fluorescence does not contribute to the phenomena studied since measurements were limited to wavelengths outside the fluorescent emission sp