The potential application of multispectral polarization imaging for detection and recognition requires a good knowledge of the depolarizing behavior of targets. We measured the degree of polarization associated to several targets in a monostatic configuration as a function of wavelength and of the angle of incidence. Depolarization effects depending on the absorption of targets were observed and a phenomenological model based on Kubelka-Munk theory is proposed. It describes the behavior of paints and diffuse materials, taking into account both contributions of surface scattering and volume scattering. Target parameters such as roughness, refractive index, scattering coefficient are taken into account and enable to draw out a predictive model of the depolarizing behavior of targets. We found a good agreement between measurements and our predictions.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.