Parchments and coloring materials in two IXth century manuscripts: On-site non-invasive multi-techniques investigation

The Kiev Folia: An interdisciplinary approach to unravelling the past of an ancient Slavonic manuscript

In the last decades, the working methods of late medieval illuminators have been widely discussed by art historians and codicologists. Non-invasive analyses are able to characterise the painting methods of illuminators as well as investigate artistic collaborations among them. The aim of this study was to characterise the painting palettes and techniques of different artists who illuminated two leaves from an early fourteenth century manuscript. The analyses were carried out with non-invasive and portable techniques such as Energy Dispersive X-ray Fluorescence (ED-XRF) spectrometry, Fiber Optics Reflectance Spectroscopy (FORS) and Raman spectroscopy. The paper highlights the differences among three rich and varied palettes and examines the pigments ultramarine, azurite, verdigris, earths, orpiment, red lead, vermillion, lead white, yellow lake, indigo, brazilwood and lac, used independently or in mixtures. We have demonstrated the effectiveness of non-invasive analyses as a tool to differentiate hands of artists who have worked on the same page. Furthermore, the comparison with analyses carried out on leaves attributed to the workshop of Pacino di Bonaguida allows to investigate in-depth the production of the main illuminators active in Florence at the dawn of the Renaissance.

Revealing Artists’ Collaboration in a 14th Century Manuscript by Non-Invasive Analyses

This interdisciplinary research on the Kiev folia, a 10th century Slavonic manuscript, shows how material and biological analyses as well as imaging methods can be applied to answer relevant questions that contribute to a better understanding of the history and conservation of ancient manuscripts. By applying non-invasive analytical methods, including X-ray Fluorescence analysis (XRF) and Fourier Transform Infrared spectroscopy in reflection mode (rFTIR), calcium oxalate related to the degradation phenomena of the ink material was detected, showing rFTIR bands at 1644 cm−1 and 1327 cm−1. Moreover, potassium ferrocyanide was identified on the peculiar blue stains visible on some folios. Multispectral images of these stains improved the legibility of the underlying letters in the near infrared range. Finally, shotgun metagenomic analyses gave insight into the possible animal origin of the skin(s) used for the manufacture of the codex and the microbiome colonizing its surface. The microbiome consisted mainly of viruses (53%) and bacteria (47%) represented by halotolerant/halophilic bacteria as well as bacteria and viruses typical of the human microbiome. In contrast, the proportion of eukaryotes (0.05%) and archaea (0.07%) was very low. This information served to determine the conservation status and the risk of deterioration of the manuscript. 

The paper presents a multi-analytical investigation of a severely degraded Jewish ritual parchment coming from a private collection. The main aim of the study was to obtain key information on the parchment manufacturing technique and original materials used, information that could help understand the historical context of the object. To this aim a series of non-invasive investigations were carried by means of multi- and hyperspectral imaging, Fourier-transform infrared (FTIR) spectroscopy and X-ray fluorescence (XRF) spectroscopy. Specific degradations as well as mapping of previous conservation treatments could be highlighted via multi-spectral imaging. Short-wave infrared images indicated the use of both iron-gall and carbon black ink, probably one related to the original writing and the other to a later intervention. To improve the imaging of degraded or partially lost text, a linear spectral unmixing classification of the HSI dataset was proposed, that showed promising results, allowing it to be applied to similar objects. XRF analysis offered an in-depth view of the chemical fingerprint of the original iron-gall ink, and critical findings on the existence of other inorganic compounds originating from the parchment manufacture. Registered FTIR data indicated denaturation of the collagen fibers, the presence of fungal-derived calcium oxalates and zinc carboxylates. In accordance with ancient Jewish parchments preparation techniques, the use of calcium sulfate, vegetable tannins and oils was also inferred from the registered infrared spectra. The corroborated results offer valuable information on the origin, production technology, and overall degradation state of the parchment manuscript. Not least, the findings could be of great interest for conservators and restorers in the field.

/pdf/application-of-spectroscopic-and-hyperspectral-imaging-510h4hryjk.pdf

Application of Spectroscopic and Hyperspectral Imaging Techniques for Rapid and Nondestructive Investigation of Jewish Ritual Parchment

Parchment is the primary writing medium of the majority of documents with cultural importance. Unfortunately, this material suffers of several mechanisms of degradation that affect its chemical-physical structure and the readability of text. Due to the unique and delicate character of these objects, the use of nondestructive techniques is mandatory. In this work, three partially degraded handwritten parchments dating back to the XIV-XV centuries were analyzed by means of X-ray fluorescence spectroscopy, µ-ATR Fourier transform infrared spectroscopy, and reflectance and UV-induced fluorescence spectroscopy. The elemental and molecular results provided the identification of the inks, pigments, and superficial treatments. In particular, all manuscripts have been written with iron gall inks, while the capital letters have been realized with cinnabar and azurite. Furthermore, multispectral UV fluorescence imaging and multispectral VIS-NIR imaging proved to be a good approach for the digital restoration of manuscripts that suffer from the loss of inked areas or from the presence of brown spotting. Indeed, using ultraviolet radiation and collecting the images at different spectral ranges is possible to enhance the readability of the text, while by illuminating with visible light and by collecting the images at longer wavelengths, the hiding effect of brown spots can be attenuated.

M. Cursi

Papers

Characterization and Digital Restauration of XIV-XV Centuries Written Parchments by Means of Nondestructive Techniques: Three Case Studies