The asymmetric four point bend (AFPB) test, which utilizes a notched specimen and is a modification of the Iosipescu test, is investigated for measuring the shear stress fringe value of orthotropic birefringent model materials. The influence of the notch parameters, such as the notch angle and the notch radius, is first studied in the case of an isotropic model material; a notch angle of 120°, with or without a radius at the notch tip, lowers the shear stress concentration and leads to a better stress fringe value compared to a 90° notch. In the case of a unidirectionally reinforced glass-polyester model material, while the shear stress fringe values given by the 90°, 120°, sharp and radiused notches are reasonably close to the value obtained for an off-axis tensile specimen, no conclusions about the influence of the notch parameters can be drawn due to the peculiarities of the photoelastic response of the inhomogenous orthotropic model material. However, the failure modes indicate that a notch radius and the 120° notch angle reduce the stress concentration. Comparison is made with finite element results.