Optical techniques are routinely applied in artworks analysis to obtain structural, morphological, and compositional information on the examined object in a non-invasive way. However, the complex structure of paintings, which can be sketched as multi-layer systems often including non-transparent layers, can hamper the penetration of the optical probe, making the non-invasive sectioning particularly challenging. Recently, cutting-edge photoacoustic (PA) methods have been tested on painted mock-ups to overcome the above-described detection limit of pure optical techniques, giving promising results. In this work, for the first time, PA measurements were taken on a nineteenth-century painting. Using a multi-modal approach, the effectiveness of the technique in revealing hidden features and providing cross-sectional measurements was assessed in comparison with other well-established pure optical techniques, namely multispectral Vis–NIR reflectography, UV imaging, fibre optics reflectance spectroscopy (FORS), optical coherence tomography (OCT), and laser scanning microprofilometry. Data integration allowed highlighting the capability of each method, proving the effectiveness of the proposed multi-modal approach. This successful application of the PA method on a real case study paves the way for its introduction among the other non-invasive techniques for paintings analysis.

光学技术通常应用于艺术品分析，以非侵入性的方式获取被检查物体的结构、形态和成分信息。然而，绘画的复杂结构，可以被描绘成通常包括不透明层的多层系统，会阻碍光学探头的穿透，使得非侵入性切片特别具有挑战性。最近，尖端的光声 (PA) 方法已经在涂漆模型上进行了测试，以克服上述纯光学技术的检测限制，并给出了有希望的结果。在这项工作中，首次对 19 世纪的绘画进行了 PA 测量。使用多模态方法，与其他成熟的纯光学技术，即多光谱 Vis-NIR 反射成像、紫外成像、光纤反射光谱 (FORS)、光学相干断层扫描相比，评估了该技术在揭示隐藏特征和提供横截面测量方面的有效性。 OCT) 和激光扫描显微轮廓测量法。数据集成可以突出每种方法的能力，证明所提出的多模式方法的有效性。PA 方法在真实案例研究中的成功应用为将其引入其他非侵入性绘画分析技术铺平了道路。和激光扫描显微轮廓测量法。数据集成可以突出每种方法的能力，证明所提出的多模式方法的有效性。PA 方法在真实案例研究中的成功应用为将其引入其他非侵入性绘画分析技术铺平了道路。和激光扫描显微轮廓测量法。数据集成可以突出每种方法的能力，证明所提出的多模式方法的有效性。PA 方法在真实案例研究中的成功应用为将其引入其他非侵入性绘画分析技术铺平了道路。