Abstract Background 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. Objective This study aims to optimize the SDCB specimen configuration to improve manageability while maintaining the quality of experimental measurements. Methods 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. Results 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. Conclusions The proposed SDCB specimen redesign offers a more manageable experimental setup, enhancing usability in experimental studies while preserving the reliability of shear behavior characterization.