A better understanding of the interaction of polarized light with biological tissue can lead to the development of valuable and minimally invasive diagnostics tools. Yet, this can be a challenging undertaking in the presence of multiply scattering. We have built a polarimetric microscope to probe multiply scattering systems In the backscattering geometry. Our apparatus has been calibrated and validated by comparing measurements to the outcomes of Monte Carlo simulations. We have recorded the spatially distributed Stokes vectors of the light backscattered from various standard samples (colloidal suspensions with varying sphere sizes, birefringent cellophane tape, etc.). To understand the behavior of these samples, we have developed: (i) a methodology that makes explicit the dependence of the polarimetric properties on the polarization state of the probing light beam; (ii) and a forward analytical model that is based on the coherency matrix and generates backscattered polarimetric patterns. Our findings demonstrate that additionally to ‘classical’ polarimetric properties (diattenuation, retardance, and depolarization), the helicity flip induced by the samples should also be included into the parametrization. This allows not only to reproduce the measurements, but also to discriminate between the different samples. Identifying the birefringent properties and structural anisotropy of the probed samples is made possible. This study is in line with research aimed at re-evaluating the polarimetric properties of multiply scattering systems and constitutes the groundwork to the accompanying contribution entitled «Polarimetric imaging of the light backscattered from multiply scattering nanofibrous PVDFhfp scaffolds».