The purpose of the present study was to characterize and simulate the hesitation effect in thin-wall molding cavities characterized by a staircase geometry (i.e., exhibiting different thicknesses along the cavity) using the experimental setup presented by Guerrier et al. [16,17], varying the processing parameters in terms of filling settings as well as the type of material, i.e., amorphous acrylonitrile butadiene styrene (ABS) and semi-crystalline polypropylene (PP).