Multi-Analytical Investigation of Painting Materials on the 21st Dynasty Wooden Coffin of Ankhefenkhonsu

The study investigates the materials of the pictorial stratigraphy and the execution techniques of the 21st Dynasty anthropoid wooden coffin of Ankhefenkhonsu, belonging to the Egyptian “yellow coffins” group and preserved in the Egyptian Collection of the National Archaeological Museum of Florence. The multi-analytical approach combines non-invasive analyses—MSI and XRF—with micro-invasive analyses—PLM, SEM-EDS, ATR-FTIR (MIR-FIR), FPA-FTIR, and GC-HRMS, including Py/GC-HRMS—to characterize pigments, binders, varnish, and alteration products. The results revealed a complex and coherent multi-layered structure consisting of a coarse brown mud ground layer, followed by a fine white calcite-based preparatory layer for the application of traditional Egyptian pigments. These include a widespread yellow pictorial layer containing orpiment, Egyptian blue, a green copper-based pigment mainly identified as atacamite, red ochre, and a carbon-based pigment. The organic compounds associated with the paint layers indicate the use of plant gums, drying oils, and natural resins, suggesting the deliberate selection and combination of different organic materials during the preparation of the pictorial films. These findings provide new insights into the material selection and painting technology of the coffin, while the identification of secondary alteration products contributes to understanding the long-term transformation of its polychrome decoration.