A final consideration concerns the values of interlaminar tensile strength: Should the user expect the two methods to yield comparable results? Not necessarily, because there are some important differences in the specimen stress states as well as the volume of material being tested. With proper alignment, the direct-loaded, flatwise tensile test produces a relatively uniform state of interlaminar tensile stress in the reduced-area test section of the specimen. This favorable stress state is present over a sufficiently large volume of material. In contrast, the indirect-loaded curved beam specimen that’s subjected to four-point flexure loading experiences a combined stress state in the curved central region that includes undesirable in-plane tension and compression stresses due to the applied bending moment. These in-plane stresses can be an order of magnitude larger than the intended interlaminar tensile stresses. Additionally, the volume of material in the region of high interlaminar tensile stress is smaller than in the flatwise tensile test.