Background <p>The out-of-plane shear behavior of paperboards plays a critical role in converting processes such as creasing and folding. The recently proposed Split Double Cantilever Beam (SDCB) specimen has been used to characterize this behavior using a cohesive zone model, but its large size poses handling challenges.</p> Objective <p>This study aims to optimize the SDCB specimen configuration to improve manageability while maintaining the quality of experimental measurements.</p> Methods <p>A design of experiments (DOE) approach and finite element analysis incorporating a mixed-mode interface model were used to analyze the influence of key specimen parameters. Shear reaction force and rotation relative to shear deformation were assessed to guide the optimization.</p> Results <p>A redesigned SDCB specimen was identified, achieving a 40% reduction in size and weight (retaining 60% of the original dimensions) without compromising the experimental quality. The optimized configuration maintained comparable measurement accuracy to the original design.</p> Conclusions <p>The proposed SDCB specimen redesign offers a more manageable experimental setup, enhancing usability in experimental studies while preserving the reliability of shear behavior characterization.</p>