The optical and visual characterization of translucent materials according to their shape and thickness is still a challenge for scientific research due to the difficulty to describe and predict in a simple manner the angular and spectral distributions of the reflected and transmitted light. In this paper, the light reflection and transmission properties of slightly scattering polymer sheets stacked with each other are studied. The light that is regularly reflected and transmitted by the material, propagated without scattering, as well as the light which is scattered out of the regular directions, are predicted using only a few measurements from a commercial reflectance/transmittance spectrophotometer and an extended two-flux model of the radiative transfer. The proposed methodology, validated by experiments, can be applied by laboratories equipped with an integrating sphere device which is usually used in the context of strongly diffusing rather than translucent materials. A discussion states the potential and the limitations of the proposed methodology.