TThis doctoral thesis project aims to implement a non-invasive analytical methodology for studying and understanding the materials and techniques present in graphic documents on translucent and lignified supports. The research endeavors to enhance the cataloging and identification of degradation processes in documents and assess the short and long-term effects of restoration treatments on the original material.

By developing a predefined methodology, the first step is to gain an in-depth understanding of the historical evolution of translucent and lignified documents. This includes exploring their materials, nature, structure, physical properties, and the mechanisms of deterioration based on the various manufacturing methods employed in the 19th and 20th centuries.

Following the selection of graphic documents from archives and collaborating documentation centers, any alterations affecting these pieces will be detected and described. Subsequently, non-invasive analytical techniques such as X-ray diffraction (XRD) and X-ray fluorescence spectrometry (XRF) will be applied to identify the inorganic materials comprising each of the studied supports. Additionally, these analyses will be complemented by examination and diagnostic imaging systems, such as hyperspectral cameras and ultraviolet illumination photography, to characterize vegetable papers formed by the addition of fatty substances.

These analyses will yield crucial data for developing actions and intervention protocols that cater to the specific needs of this type of material. Furthermore, they will contribute to enhancing the conservation and restoration systems of the studied collections. The ultimate goal is to conduct multidisciplinary research of interest, and to achieve this, the results will be disseminated to both specialized and non-specialized audiences, as well as to relevant sectors like technological development companies, restorers, archives, museums, and libraries. The generated data will be incorporated into a database accessible to other researchers.

The novelty of this proposal lies in implementing non-invasive in situ characterisation analyses and improving data interpretation to enhance knowledge and amplify the value of this documentary typology. This includes plans, maps, tracings, treated canvases, and contemporary works significantly affected by the instability and fragility of their materials.