Visualizing underdrawings in medieval manuscript illuminations with macro‐X‐ray fluorescence scanning

Abstract

The element‐specific distribution maps generated by scanning macro‐X‐ray fluorescence (XRF) spectroscopy are providing cultural heritage researchers with information about the composition of materials present in works of art and, more importantly, unprecedented insight into the techniques employed by artists in their creation. One of the advantages of macro‐XRF scanning is that the X‐rays probe materials in subsurface layers, allowing, for example, visualizations of hidden paintings to be produced. Consequently, macro‐XRF scanning has found wide use in the study of paintings, but the high spatial resolution also makes it particularly well suited for the study of the small‐scale painted illustrations and decorative elements found in illuminated manuscripts. The preliminary drawings made by manuscript illuminators to plan a painted composition—known as underdrawings—provide evidence relating to artists' creative vision and working process but are difficult to examine because they are generally hidden under the surface paint layer. Traditionally, underdrawings in a carbon‐based medium are visualized using infrared (IR) imaging. In this study, results of the analysis of painted illuminations from medieval illuminated manuscripts demonstrate that macro‐XRF scanning can visualize underdrawings in other materials, such as iron‐gall ink, metalpoint, and pigmented inks/paints, thus serving as a useful complement to traditional IR imaging. For manuscript illuminations in bound books, this study also discusses the use of interleaving materials to reduce unwanted signals from underlying folios. The ability to reveal manuscript underdrawings will help elucidate artistic intent and workshop practice and provide a new way to examine the history of medieval drawing.

Application of Multispectral Imaging and Portable Spectroscopic Instruments to the Analysis of an Ancient Persian Illuminated Manuscript

“…For these studies, the most widely used methods are imaging techniques: multispectral and hyperspectral applications [2][3][4][5][6][7][8][9] and spectroscopic techniques (e.g., XRF, FORS, Raman) using portable and lab equipment [10][11][12][13][14][15][16][17][18][19][20]. In general, most of the scientific studies carried out thus far on manuscripts of different periods and geographical areas have concerned the analysis of the inks [21], the variety and distribution of pigments in the decorations, in some cases, the identification of the techniques of realization, and sporadically, the study of the paper.…”

Visualizing and measuring gold leaf in fourteenth- and fifteenth-century Italian gold ground paintings using scanning macro X-ray fluorescence spectroscopy: a new tool for advancing art historical research

“…Importantly, the element distribution maps generated by this technique can also provide new information that results in abetter understanding of other aspects of an artist's technique. For example, scanning MA-XRF as well as other spatiallyresolved imaging spectroscopies has allowed for the visualization of preliminary or abandoned versions of compositions, revealed the sequence in which paint layers were applied, and even helped track changes that may have occurred over time [12][13][14][15][16][17][18][19][20]. In this work, the use of MA-XRF imaging spectroscopy to visualize individual gold leaves in Italian panel paintings was explored.…”

Visualising Iron Gall Ink Underdrawings In 16th Century Paintings In-Situ By Micro-XRF Scanning (MA-XRF) And LED-Excited IRR (LEDE-IRR)

“…Nevertheless, the joint presence of side elements such as Cu and Zn could distinguish between different Fe-containing underdrawing materials such as ochres and iron gall inks. The visualisation of lost scriptures written with iron gall ink in palimpsests [18][19] or of iron gall ink underdrawings underneath manuscript illuminations [20] by MA-XRF hint at the potential success for visualising the distribution of iron gall ink underdrawings in paintings. This is also supported by published MA-XRF results of Leonardo da Vinci's "Madonna of the Rocks" from the National Gallery London, which revealed the distribution of a Zn-containing underdrawing material, that has not yet been further specified [21].…”