Evolution of Colorimetry in 3D-Printed Samples Exposed to External Weather Conditions, Used in Smart Façades

The successful deployment of 3D printing in outdoor applications is contingent upon the selection of materials capable of withstanding the degrading effects of weather. This study evaluates the colorimetric performance of various 3D-printed polymers exposed to natural weathering conditions in Brasov, Romania, from November 2024 to March 2025. Color changes were monitored through spectrophotometry using a PCE-XXM 20 color meter, and data were recorded in the LAB color space. The results indicate substantial differences in color stability among the tested materials, with some exhibiting unacceptable levels of fading and discoloration. These findings have significant implications for the design and implementation of outdoor 3D-printed products in climates analogous to that of Brasov, underscoring the importance of selecting materials with demonstrated resistance to weathering and color change.