A careful analytical study of the paint materials used in medieval illuminated manuscripts and their respective formulations is critical to their preservation. Due to their high value and fragile nature, access to these objects is often limited. Therefore, the development of ad-hoc methodologies allowing researchers to collect data in the least invasive way possible is an essential task in conservation science. This article shows the potential of a combined approach that complements handheld Raman spectroscopy with micro-SORS for the characterization of medieval paints. This methodology was tested on a reference collection of mock-up samples prepared as pure, mixture, and layered paints on parchment, based on historical information regarding paint formulations from Iberian scriptoria. Conventional Raman analysis, carried out by means of two handheld spectrometers, was found particularly effective for materials identification in pure paints and multi-component formulations of increasing complexity. Complementing this data, micro-SORS proved decisive in differentiating between mixture and layered paints in most mock-ups examined, yielding detailed information about the stratigraphy of reference samples produced through the overlaying of different paints. This combined methodology may be helpful to researchers who would like to approach the vibrational characterization of paints applied onto fragile artifacts and supports in a totally non-invasive manner.

中文翻译：

---

羊皮纸上中世纪绘画振动表征的组合方法：手持式拉曼光谱和微型 SORS

对中世纪彩绘手稿中使用的油漆材料及其各自的配方进行仔细的分析研究对于它们的保存至关重要。由于它们的高价值和易碎性，这些物品的获取通常受到限制。因此，开发特殊方法使研究人员能够以尽可能侵入性最小的方式收集数据是保护科学的一项重要任务。本文展示了一种组合方法的潜力，该方法可补充手持式拉曼光谱与微型 SORS 来表征中世纪涂料。该方法根据伊比利亚文献中有关涂料配方的历史信息，在羊皮纸上制备为纯涂料、混合涂料和分层涂料的模拟样品参考集合上进行了测试。人们发现，通过两台手持式光谱仪进行的传统拉曼分析对于纯涂料和日益复杂的多组分配方中的材料识别特别有效。作为对这些数据的补充，事实证明，在大多数检查的模型中，微型 SORS 在区分混合涂料和分层涂料方面具有决定性作用，从而提供了通过叠加不同涂料而产生的参考样品的地层学详细信息。这种组合方法可能有助于研究人员以完全非侵入性的方式研究应用于易碎文物和支撑物上的涂料的振动特征。