As with any historical field, despite the sheer quantity of evidence you may collect, there will always be parts of the past that remain shrouded in mystery. This is of course true for manuscripts; even if we combined all our current knowledge, we will never quite manage to uncover each and every hidden facet of a sheet of parchment. However, there are individuals within the field leading research with the use of science – more specifically, using Raman spectroscopy to study the pigments used in manuscripts. During my fortnight’s internship at the Parker Library, I had the pleasure of observing the work of Richard Gameson, Andrew Beeby, and Catherine Nicholson. I came to learn that through identifying the materials used to create pigments for illuminations in medieval manuscripts, we can better understand the techniques of the illuminator or scribe, the skill of those within the craft, and also gain an insight into where such materials were bought and traded from geographically.
Spectroscopy has enabled research over an expansive palette of manuscripts, and complementary documents such as financial accounts and histories of the institutions the manuscripts originated from, lets us conclude whether the pigment was chosen due to availability, cost, or ease of manufacturing.
Unfortunately, there are several obstacles that arise when studying manuscripts. Parchment, made from the skin of animals (in England, typically that of a sheep or cow), is incredibly delicate and susceptible to damage; some of the inks used damage the substrate irreparably as the page is exposed to light and oxygen. Nevertheless, working with medieval manuscripts requires that they be exposed to light, and come into contact with both people and scientific apparatus. Previous scientific enquiry has caused damage, from the reagents used in the 20th century, to samples which were snipped from the corners of manuscripts more recently; however, in the past decade, an alternative has been offered. Raman spectroscopy, combined with hyperspectral imaging and diffuse reflectant spectroscopy, allows for a detailed analysis of a minute section of manuscript, whilst causing the smallest amount of exposure and damage. By aiming a low intensity laser beam at a point in the manuscript no larger than a millimetre, the wavelengths that ‘bounce’ back are indicative of what compound (or compounds) make up the pigment under analysis. Such analysis is particularly useful when studying pigments used in manuscripts produced in the British Isles and northern Europe between the seventh and fifteenth centuries.
Canterbury, being chosen by St Augustine as the seat of the early Christian church in England, developed into an area of expansive wealth, a historical fact which is evident in the manuscripts that were produced there. The Dover Bible (CCCC MS 3 & MS 4), was split into two volumes, both of which measure over half a metre long, and together consist of almost 300 parchment bifolia, a number which is roughly equivalent to the number of cow hides which would be necessary to produce the manuscripts.
As these two volumes are also home to some of the brightest and most intricate illuminations of the twelfth century, their analysis can provide a stunning insight into pigments used in the medieval period immediately after the Norman Conquest. Though considerable study has been carried out without the use of Raman spectroscopy, this added layer of scientific inquiry has become invaluable to researchers.
Looking at contemporary financial and import records determines that lapis lazuli, a bright blue pigment imported predominantly from Afghanistan, was the most frequently used source of blue in illuminations in Canterbury manuscripts. The sheer cost of the material resulted in the pigment being deployed in two ways; sparingly in cheaper manuscripts, often only being used for depictions of God, saints, and other key biblical figures, and more liberally in manuscripts that aimed to demonstrate the overflowing wealth of the institution that made or commissioned it. However, it is known that blue paint could also be made using a pigment called ‘Egyptian blue’, which was found in pre-existing materials such as antique glass or pottery, and ground up before being added to the paint medium. This poses the issue that when looking at the colour blue on a manuscript with the naked eye, lapis lazuli and Egyptian blue look completely the same. Raman spectroscopy arrives somewhat like a lamp to lighten the darkness and uncertainty around these pigments. When looking at the Dover Bible in particular, it is shown that lapis lazuli was the pigment of choice. This is complementary to the knowledge that the Dover Bible was made by Canterbury for the small neighbouring dependency, the Priory of Dover, demonstrating a wealth so immense they can pay for luxurious manuscripts not just for themselves, but for others as well.
The issue of two different sources of the same colour being virtually indistinguishable from each other is not limited to blue. Throughout the first and middle half of the twelfth century, vermillion (cultivated from cinnabar) and red lead were also two different compounds that could be used to create red paint.
In some cases a difference can be seen at first glance – vermillion can be mixed to create a striking blood-red, whereas red lead gives way to a more orange tone, allowing for contrast. However, deeper analysis using Raman spectroscopy has shown us that they can also appear in paint mixed together, or used in identical shades, but on different sections of the same manuscript, as demonstrated in the Dover Bible.
Mixing of different compounds to create variety in a colour’s shade is a common method in the Dover Bible. Research on various twelfth century manuscripts from the Canterbury area has shown that grey-blue was created using lapis mixed with ash, and for pure grey, such as human hair or a cloak, lapis was mixed with orpiment (yellow). The mixing of two pigments together is not just reserved for blues and greys. Green can be formed in two ways; firstly though the use of copper, or, with vergaut (a mix of orpiment and indigo). When looking at Canterbury manuscripts as a whole, spectroscopic research has shown that copper greens dominated throughout the post-Norman period.
However, vergaut green did reappear around 1100 AD in some Canterbury manuscripts, but was now made by combining orpiment with lapis lazuli, rather than indigo. It is unlikely, knowing that lapis could only be imported from Afghanistan, that the choice to create vergaut from lapis was a decision that sprung from availability; more likely, it was to demonstrate the wealth and status of the institution. This assessment could only have been made by using the data that Raman spectroscopy provided as greens, like blues, are very difficult to discern with human eye alone.
Spectroscopy has also shown us that the copper green in the Dover Bible particularly was further modulated with the addition of white lead. White lead was used as part of the richer palettes seen in eleventh and twelfth century manuscripts – for example, it is used in the Dover Bible to add highlights, minute detail such as the whites of the eyes, and mellow the green of the borders. Study of other Canterbury manuscripts has shown that varying concentrations of green pigment itself could create different tones, but the use of white lead to alter the shade is dominant in the Dover Bible.
The concluding note of this article strays further than the Dover Bible; the research of Gameson and Beeby has extended far beyond Canterbury manuscripts. Studying the past requires us to surrender the idea that fact is always fixed. Even conclusions that have been considered infallible for several decades can be uprooted using new methods of research. Raman spectroscopy is no exception, and allows us to look at manuscripts in a way we could not before – to loosely quote Gameson, ‘shed new light on old illuminations’.
-Megan Webb
(mhgw2@cam.ac.uk)
Bibliography:
- Beeby, Andrew and Gameson, Richard and Nicholson, Catherine. Illuminators’ pigments in Lancastrian England. ‘Manuscripta’, 60 (2). pp. 143-164. (2016)
- Beeby, Andrew, Gameson, Richard & Nicholson, Catherine. Colour at Canterbury: the Pigments of Canterbury Illuminators from the Tenth to the Twelfth Century. ‘In Manuscripts in the Making. Art & Science 1’. Panayotova, Stella & Ricciardi, Paola Harvey Miller – Brepols. 21-35. (2017).
- Nicholson, Kate, Beeby, Andrew and Gameson, R. G. (2016) ‘Shedding light on medieval manuscripts’. Spectroscopy Europe, 28 (4). pp. 6-8.
- ‘Meetings with Remarkable Manuscripts’, Christopher de Hamel, Penguin UK, (2016).
- ‘The Cambridge Companion to the History of the Book’, Materials and meanings, Stoicheff, Peter. ed. Howsam, Leslie. Cambridge University Press, (2015).
- ‘The Book in Britain, Volume II, 1100-1400’, Illumination – pigments, drawings, and gildings, Morgan, Nigel. ed. Morgan, & Thomson, Cambridge University Press (2008).
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