The characterization of the plastic behaviour of rolled metal sheets at large strains is a critical ingredient of any finite element analyse software aimed at predicting stress and strain distributions and the eventual occurrence of defects in sheet metal forming. On the other hand, due to the reduced thickness of such rolled sheets, the experimental techniques available for their characterization are scarce. Recently, however, the development of reliable simple shear tests has brought a real breakthrough in this area. The present paper shows how two-stage non-proportional loadings involving sequences of simple shear and/or uniaxial tensile deformations can be adequately used to investigate the isotropic, kinematic and distortional hardening of rolled metal sheets at moderate and finite strains. The experimental techniques and their optimization are analysed and several examples concerning currently used structural materials are provided.