The use of ground glass in red glazes: structural 3D imaging and mechanical behaviour using optical coherence tomography and nanoindentation

Abstract In this study we investigate the impact of addition colourless glass particles to red glazes, as seen in many 15th-17th-century easel paintings. With use reconstructions, examined influence paint preparation process on morphological and mechanical properties film. Three sets reconstructions were made, a control without ground glass, with coarse or fine mixed in, where was jointly pigment oil mixture. The latter gave desired consistency colour based visual inspection. dried non-invasively imaged using optical coherence tomography (OCT). A data-analysis pipeline developed for both segmentation OCT images measurement size spatial distributions within glaze layer. Moreover, used nanoindentation protocol measure viscoelastic results show an expected decrease median particle longer grinding-time, which additional grinding pigment/oil resulted more narrow distribution homogenous particles. indicate that increases elastic viscous moduli layers. homogeneous distribution, obtained by oil, pigment, together, induces higher moduli. Our imaging analyses approach, combining nanoindentation, provides non-invasive quantitative investigation (semi-) transparent layers, their effect glaze. contribute better understanding artists’