The following post is by Cindy Connelly Ryan and Meghan Wilson, preservation science specialists in the Preservation Research and Testing Division with Marianna Stell, reference librarian in the Rare Books and Special Collections Division
Advances in scientific instrumentation permitting non-invasive micro-scale analysis are bringing a revolution to the scholarly understanding of the texts and images of medieval manuscripts, wherein investigating the materiality of the original object unlocks new information about its current condition, its original making, and its meaning. A dramatic example is this diminutive devotional miscellany manuscript in the Library’s Lessing J. Rosenwald Collection.
Rosenwald manuscript 13, Betrachtungen des Leidens Christi und Gebete für Klosterfrauen (Contemplations of the Passion of Christ and Prayers for Nuns) contains six drawings and seven hand-colored woodblock prints, all of which have been removed from other sources and pasted into this small, hand-written paper manuscript. These pasted devotional images make Rosenwald 13 a particularly interesting example of a manuscript crafted for devotional purposes and used and re-used over several centuries within the context of a female religious community probably located in the Upper Rhine area of Europe.
Nested among the many-pasted paper elements in Rosenwald 13, one image painted on parchment stands out as being exceptional: The Holy Face, also known as the veil of Veronica, or the sudarium of St. Veronica.
Removed from its original context and reused in this manuscript for a specific devotional use, the Holy Face in Rosenwald 13 may have once included reference to the veil, such as in this image of a Flemish manuscript from the Getty Museum of Art.
This visual convention originates with the legend of Saint Veronica, who wiped the face of Christ with her veil (or sudarium) as he carried the cross to Calvary. Miraculously, Veronica’s veil retained Christ’s portrait, like a painting left on the cloth that had pressed against his face. Considered an authentic likeness of Christ’s face, the veil with its image became one of the most popular and precious visual traditions of the Middle Ages.
Attached to leaf 58v of Rosenwald 13, the image of the Holy Face presents its viewers with something unusual within the Holy Face convention: Christ’s face, hair, and rays of the nimbus (halo) appear in shades of black and gray.
A similar image of the Holy Face is known in an East Anglian manuscript leaf now housed at the Getty Museum in Los Angeles, California, and other in the Van Reynegom Book of Hours (page 25) now at the King Baudoin Foundation, but examples are not plentiful or well-studied.
Specialists in the Rare Book and Special Collections Division asked for scientific aid in determining whether the Rosenwald example reflects a choice of pigment on the part of its fifteenth-century creator, or whether the coloration is the product of alteration over time – the tarnishing of a metal leaf, for example, or the blackening of lead-based pigments.
The tarnishing of metal leaf and the darkening of some metal-based pigments are well-known preservation issues that can significantly alter the reading of an image. If red and white lead pigments are used to render the tones of a face, degradation can change the original colors dramatically.
In the case of the Holy Face in Rosenwald 13, however, analysis has revealed that change over time is only part of the answer. The dark appearance of Christ’s nimbus is indeed an alteration; but the color of Christ’s face is not! The dark pigment is intentional.
How do we know this?
The dark triangular flanges of the nimbus were identified by x-ray fluorescence spectroscopy (XRF) as sulfur-blackened silver leaf, applied over a thick ground of dark brown material visible in areas of metal loss. This under-layer may be a clay toned with pigments, as often used under gold leaf, or a naturally dark earth.
By contrast, the dark gray and black colorants used for the face and the hair appear to be in their original condition. No evidence was found of an altered metal leaf or metallic pigment in either the face or the hair – no silver, tin, nickel or mercury are present. While there is certainly sulfur present, there are only traces of lead, not enough to suggest a darkened lead foil or lead-based pigments. The small dots of lead white paint under the eyes, which would be quite sensitive to such discoloration, show no evidence of this, supporting the interpretation that the face’s dark appearance is original.
Elsewhere in the painting, PRTD staff identified the use of azurite blue, brazilwood and vermilion reds, and the lead white details, using a combination of reflectance spectroscopy, XRF, and multi-spectral imaging. The writing ink and the printed woodcut lines are both iron gall inks, although not the same batch of ink, based on their trace elements.
In both the hair and the face, uncommon materials or mixtures appear to have been used, rather than the familiar black media of the period: carbon black, iron gall ink, black earths, or black chalks. This use of uncommon black pigments has an interesting parallel: PRTD’s previous study of Rosenwald collection 15th century block-printed books found a unique black pigment rich in iron and copper used in the Art of Memory. That colorant shows some superficial similarity to the reflectance spectrum from the hair of this woodblock, though the peak positions do not fully correlate, and their XRF elemental profiles differ.
Rosenwald 13 and the block books both come from a period of creativity and experimentation with methods of book production in Germany, as expanding literacy in the middle class drove a market for producing books more rapidly, in larger numbers, and with less-skilled labor. Moveable type, hand lettering, woodblock, pasted-in elements, stenciling, or hand-coloring may be found in diverse combinations within a single volume, and in both the block books and this manuscript, PRTD has found evidence of experimentation with novel colorants.
Eliminating the possibility of color degradation in the pigment in the painting of the Holy Face on Rosenwald 13 allows the specialists in the Rare Book and Special Collections Division to analyze the theological and devotional context in a new way. While in Eastern Christianity the Holy Face was used as a justification for the use of images against threats of iconoclasm, in the late Middle Ages in Europe, the Veil of Veronica became associated with arguments for the real divine presence existing within material objects. The use of dark pigments within this conversation – particularly within the context of late medieval German female monastic devotion – is one that adds more than just color.
This small scientific study illustrates the importance of the Preservation Directorate’s mission to maintain items in their original condition and format, so that future scholars using future generations of increasingly advanced methods of study will be able to extract ever-deeper layers of meaning from them.
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