Birefringent Properties of 3D-Printed Polymers Fiedler, Johannes Blachowicz, Tomasz Ehrmann, Andrea linear birefringence 3D printing fused filament fabrication (FFF) stereolithography (SLA) crossed polarizers Birefringence describes the optical properties of optically anisotropic or chiral materials. As linear birefringence is a measure of anisotropy in the structure of a glass or a polymer, stress induced in glasses or polymers can be measured by stress birefringence. Interestingly, this effect can also be found in 3D-printed materials, such as fused filament fabrication (FFF)- or stereolithography (SLA)-printed objects, for some materials or material blends. Here, we report birefringence measurements on 3D-printed translucent objects, performed using a microscope with crossed polarizers as well as large-scale crossed polarizers, and show visual differences between macroscopic and microscopic effects. MDPI 2026 info:eu-repo/semantics/conferenceObject doc-type:conferenceObject text http://purl.org/coar/resource_type/c_5794 https://www.hsbi.de/publikationsserver/record/7188 https://www.hsbi.de/publikationsserver/download/7188/7189 Fiedler J, Blachowicz T, Ehrmann A. Birefringent Properties of 3D-Printed Polymers. In: <i>ICNDT 2026</i>. Vol 156. Basel Switzerland: MDPI; 2026:3. doi:<a href="https://doi.org/10.3390/engproc2026156003">10.3390/engproc2026156003</a> eng info:eu-repo/semantics/altIdentifier/doi/10.3390/engproc2026156003 info:eu-repo/semantics/openAccess