Non-invasive stratigraphic analyzes of gelatine-based modern painting materials with linear and nonlinear optical methods
Year: 2024
Authors: Balbas DQ; Maestro-Guijarro L; Carmona-Quiroga PM; Oujja M; Castillejo M; Bettini F; Porcinai S; Striova J
Autors Affiliation: CNR, Natl Inst Opt CNR INO, Largo E Fermi 6, I-50125 Florence, Italy; CSIC, Inst Quim Fis Blas Cabrera IQF, C Serrano 119, Madrid 28006, Spain; Opificio Pietre Dure MiC, Lab Restauro Dipinti Tela & Tavola, Viale F Strozzi 1, I-50129 Florence, Italy; Opificio Pietre Dure MiC, Sci Lab, Viale F Strozzi 1, I-50129 Florence, Italy.
Abstract: Stratigraphic analyzes of polychrome surfaces, such as paintings, often need samples to offer consistent results regarding the sequence and composition of the layers. Non-invasive methodologies based on linear and nonlinear optical techniques limit material removal from the objects. Recently, optical coherence tomography (OCT) has become the preferred choice of heritage scientists because it is a safe and fast alternative for studying transparent or semi-transparent layers. Yet, nonlinear optical microscopy (NLOM)) technique in its modality of multiphoton excitation fluorescence (MPEF) has emerged as a promising tool for the same purpose. Here, we explored linear (OCT and confocal Raman microspectroscopy (CRM)) and nonlinear (NLOM-MPEF) optical methods’ capability to investigate gelatine-based layers in mock-up samples and a painting dated 1939 by an artist from the Surrealistic entourage. The optical behavior of mock-up samples that imitate the painting stratigraphy and of six painting fragments detached from the support was also investigated with fiber optics reflectance spectroscopy and laser induced fluorescence (LIF). Thickness values from the mock-ups obtained with OCT, CRM, and MPEF have provided evidence of the complementarity, from a millimetric to a micrometric scale, and the limitations (e.g. strong fluorescence emission in CRM) of the methods. Moreover, the presence of gelatine was ascertained by LIF spectroscopy applied to the painting fragments and NLOM-MPEF confirmed its suitability as a non-invasive technique for investigating gelatine-based stratigraphic systems.
Journal/Review: JOURNAL OF PHYSICS-PHOTONICS
Volume: 6 (3) Pages from: 35018-1 to: 35018-13
More Information: Financial support by the Access to Research Infrastructures activity in the Horizon 2020 Programme of the EU (IPERION HS Grant Agreement n.871034) is gratefully acknowledged.KeyWords: NLOM-MPEF; OCT; gelatine; confocal Raman; modern painting; cultural heritageDOI: 10.1088/2515-7647/ad5772