This document discusses 3D photoelasticity and integrated photoelasticity techniques. It describes how a 3D model of a mechanical joint is fabricated using epoxy resin, assembled and loaded to induce stresses, and then frozen to preserve the stress state. Slices are cut from the frozen model and analyzed using integrated photoelasticity. This technique determines characteristic retardation and rotation parameters by constructing and comparing Jones matrices representing the optical behavior of the 3D model and equivalent optical elements. The stress distribution within the model can then be determined by assuming a field and solving the equations relating the experimental parameters.