Citation: Delledonne, C.; Albano, M.; Rovetta, T.; Borghi, G.; Gentile, M.; Marvelli, A.D.; Mezzabotta, P.; Riga, L.; Salvini, E.; Trucco, M.; et al. Rediscovering the Painting Technique of the 15th Century Panel Painting Depicting the Coronation of the Virgin by Michele di Matteo. Heritage 2024, 7, 324–337. https://doi.org/10.3390/ heritage7010016 Academic Editors: Silvano Mignardi, Laura Medeghini, Wenke Zhao, Laura Calzolari and Melania Di Fazio Received: 5 December 2023 Revised: 30 December 2023 Accepted: 4 January 2024 Published: 10 January 2024 Copyright: © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). heritage Article Rediscovering the Painting Technique of the 15th Century Panel Painting Depicting the Coronation of the Virgin by Michele di Matteo Chiara Delledonne 1,2 , Michela Albano 2,3 , Tommaso Rovetta 2 , Gianmarco Borghi 4 , Mario Gentile 4 , Anna Denia Marvelli 4 , Piero Mezzabotta 4 , Lucia Riga 4 , Elisa Salvini 4 , Marta Trucco 4 , Francesca Volpi 2,3, * and Giacomo Fiocco 2,3 1 Department of Physics, University of Pavia, Via Agostino Bassi 6, 27100 Pavia, Italy; chiara.delledonne@unipv.it 2 Arvedi Laboratory of Non-Invasive Diagnostics, CISRiC, University of Pavia, Via Bell’Aspa 3, 26100 Cremona, Italy; michela.albano@unipv.it (M.A.); tommaso.rovetta@unipv.it (T.R.); giacomo.fiocco@unipv.it (G.F.) 3 Department of Musicology and Cultural Heritage, University of Pavia, C.so Garibaldi 178, 26100 Cremona, Italy 4 Laboratory of Applied Diagnostics for Cultural Heritage, Cr.Forma Restoration School, C.so Matteotti 17, 26100 Cremona, Italy; borghigianmarco00@outlook.it (G.B.); mario.gentile@studenti.unimi.it (M.G.); annadenia.marvelli@studio.unibo.it (A.D.M.); piero.mezzabotta@gmail.com (P.M.); lussi76@yahoo.it (L.R.); elisasalvini@fadbrera.edu.it (E.S.); martatrucco@outlook.com (M.T.) * Correspondence: francesca.volpi@unipv.it Abstract: The study concerned a diagnostic spectroscopic campaign carried out on the panel painting depicting the Coronation of the Virgin (first half of the 15th century) by the late-Gothic Italian painter Michele di Matteo. The main aims were the identification of the original painting materials and the characterization of the painter’s artistic technique. A combined approach based on non- and micro-invasive techniques was employed. Visible and ultraviolet-induced fluorescence photography was used to select the areas of interest for spectroscopic analyses; X-ray radiography assessed the state of conservation of the support, while X-ray fluorescence and external reflection Fourier transform infrared spectroscopies allowed the chemical identification of pigments, binders, and varnishes. At- tenuated total reflection infrared spectroscopy, optical microscopy, and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy were used to visualize and characterize the materials in the pictorial layers. The results highlighted the presence of pigments, possibly applied with an egg binder, consistent with the period of the production of the painting, as well as modern pigments used during subsequent restorations: an imprimitura with lead white and a gypsum-based ground layer. Concerning the gilding, the guazzo technique was confirmed by identifying a red bolo substrate and gold leaf. Keywords: panel painting; multi-analytical approach; XRF; ER-FTIR; ATR-FTIR; optical microscopy; electron scanning microscopy 1. Introduction In the field of cultural heritage, the analytical scientific approach is often used to support conservation and restoration procedures, as well as to increase the information useful for the art historical study and valorization of an artwork. This type of analysis often focuses on the identification and characterization of the different materials used to produce the artwork and their distribution in the multi-layered system present in different areas of the painting. In the case of medieval panel paintings, the stratigraphic system usually includes a ground layer (e.g., gypsum and glue), an under-drawing, overlapped paint layers, a mixture of pigments and binding media (e.g., animal glue, egg, siccative oil), and an external varnish that partially covers non-original paints or restoration materials [1–5]. Heritage 2024, 7, 324–337. https://doi.org/10.3390/heritage7010016 https://www.mdpi.com/journal/heritage