A close look at a small English manuscript

The Fitzwilliam Museum holds an exceptional collection of medieval and Renaissance manuscripts, representing all major schools of European illumination from the ninth to the sixteenth century. In the last decade, hundreds of volumes have benefited from interdisciplinary study undertaken as part of two ongoing projects, Cambridge Illuminations and MINIARE.

In this context, the Fitzwilliam’s scientific team recently analysed some fifteenth-century English manuscripts in order to investigate the illuminators’ materials and techniques. Among them, we took a close look at a volume which attracted our attention for its dimensions, only about 10 x 7 x 3 cm! (Fig. 1).

Figure 1. MS 2-1967

The manuscript (MS 2-1967) is a Book of hours dating to c. 1420, written in Latin on 184 folios of parchment. It contains seven historiated initials, numerous minor decorated initials, pen-work infills of different colours, and borders with golden ivy leaves and coloured acanthus leaves (Fig. 2). Most folios display some level of degradation, in the form of darkening of the red-orange areas and flaking gold leaf, which has significantly changed the original appearance of the decorated borders.

Figure 2. MS 2-1967, fol. 40r (left) and fol. 114r (right). A close look at both folios reveals some design differences in the historiated initials. On fol. 40r, the lower part of the scene extends below the coloured initial and is only partially surrounded by a gilded frame, whereas on fol. 114r, the large initial encloses the miniature and is entirely framed with gold. This may have been a way for a single artist to showcase creativity, or suggest the work of different artists.

In order to characterise the manuscript’s palette, we examined folios which had been selected by the Keeper of Manuscripts as representative of the  style and colours of the manuscript’s illuminations. We chose a fully non-invasive protocol, i.e. we selected analytical methods that do not require the removal of physical samples or contact with the object’s surface. The analytical protocol included near infrared imaging, reflectance spectroscopy in the ultraviolet, visible, and near-infrared range and X-ray fluorescence spectroscopy (XRF) (Fig. 3).

Figure 3. Preparation for XRF analysis. In order to avoid interference from text and decorations present on the underlying pages, a disc of Plexiglas was carefully laid between the page under analysis and the following one, with a leaded weight securing it in a stable position. Due to the small dimensions and opening characteristics of the manuscript, it was not possible to analyse those areas painted very close to the spine.

The results of the technical investigation revealed a rich palette, which includes lead white, carbon black, vermilion red, and red lead. The latter has often degraded, especially in the borders, and now appears black. An organic red dye was used to paint pink and red passages, whereas a purple dye was employed for lilac pen-work infills surrounding small gilded initials and to rule the pages.

Ultramarine is the main blue pigment used within the illuminations and the text, e.g. to paint all the blue garments and the acanthus leaves. Interestingly, XRF analysis revealed that the ultramarine employed for the small initials within the text contains more calcium than other blue areas analysed. Calcium may derive from calcite, one of the most common minerals associated with the natural stone lapis lazuli, from which ultramarine is made. Its presence may suggest the use of a low-quality ultramarine, prepared or sourced differently than other batches of the same pigment1.

Figure 4. MS 2-1967, fol. 40r. Photomicrograph showing the resurrected Christ. Flesh tones were obtained with a few brown outlines, red dabs, and white highlights; shell gold was used to enrich the red background.

Blue azurite mixed with lead white was found only in small passages, such as the light blue armours of the soldiers witnessing the resurrection of Christ on fol. 40r (see Fig. 2). Azurite was also mixed with an earth pigment to obtain the dark green used in the foreground of all scenes depicted in the historiated initials analysed. An earth pigment, mixed with various compounds, also yielded yellow and brown hues.

Figure 5. MS 2-1967, fol. 40r. Photomicrograph showing one of the soldiers seated outside the Holy Sepulchre looking with astonishment at the resurrected Christ. Brown and yellow hues were obtained using an earth pigment mixed with a copper-based compound and lead white.

A copper-based compound was employed to obtain the bright green leaves of the borders. Its reflectance spectral signature most resembled that of a mineral compound – such as malachite or a copper sulphate –  rather than a synthetic product, such as Verdigris.

Gold was found to be used as shell gold (i.e. powdered gold used as ink or paint) and as gold leaf (i.e. gold beaten into thin sheets), which was laid over a raised white ground. Lastly, iron-gall ink, containing copper and zinc, and red vermillion were used in the text.

Along with the imaging and spectroscopic techniques listed above, microscopic observation helped clarify the illuminator’s painting techniques. Flesh tones were painted using lead white, in addition to a copper-containing compound, an iron-oxide pigment, and small amounts of a calcium-based pigment (such as chalk or gypsum). Outlines and facial features were likely to have been drawn with iron-gall ink; lips, cheeks, and noses were enriched with dabs of red lead, and highlights were then added using lead white.

Figure 6. MS 2-1967, fol. 114r. Photomicrograph showing one of the mourners attending a funeral. Carbon black was used to paint the mourner’s black cloak.

Among the materials detected, two are of particular interest: the copper-containing mineral used for bright green areas, and ultramarine. Both pigments are not commonly encountered in fifteenth-century English manuscripts, which often contain Verdigris and azurite2 instead. Ultramarine remained the standard blue pigment used by illuminators until the late thirteenth century, when it was replaced by azurite, possibly due to the disruption of trade routes between Europe and Asia – the primary source of this pigment – after the disintegration of the Mongol Empire3. The extensive use of precious ultramarine within the manuscript therefore raises questions about the context of its production and the patron’s social status, potentially suggesting a prestigious commission. Additionally, observation under magnification revealed the artist’s ability to portray different expressions and ultimately suggest emotions, such as joy (Fig. 4), astonishment (Fig. 5) or sorrow (Fig. 6), in very tiny faces – they are only a few millimetres long!

Overall, the results of the analyses allowed us to gain insight into the material choices made by a fifteenth-century English illuminator to enrich a book of private devotion. In addition, they will broaden knowledge about English manuscripts produced in that century which have not yet benefited from in-depth examinations.

Even if at first glance the manuscript seemed easy to handle and examine, and the original palette easy to identify, this research taught us that sometimes small objects contain unexpected treasures!

Mila Crippa
Zeno Karl Schindler/MINIARE Fellow
mc2154@cam.ac.uk

References

Osticioli, I. , N.F.C Mendes, A. Nevin, F. Gil, M. Becucci, E. Castellucci, ‘Analysis of natural and artificial ultramarine blue pigments using laser-induced breakdown and pulsed Raman spectroscopy, statistical analysis and light microscopy’, Spectrochimica Acta Part A 73, 2009, 525-531.

Panayotova, S., L. Pereira-Pardo, P. Ricciardi, ‘Illuminator’s Materials and Techniques in Fourteenth-century English Manuscripts’, in Manuscripts in the Making: Art and Science, eds. S. Panayotova and P. Ricciardi, London and Turnhout: Harvey Miller/Brepols, 2017, vol. 1, 46-64.

It’s on my Christmas list: The Hirox 3 D Digital Microscope

Earlier in the year a small group of Fitzwilliam conservators were given  fascinating insight into the new and latest Hirox 3D Digital Microscope, PC Edition (RH-2000). A pretty sophisticated bit of ‘non destructive analytical kit’ by any comparison. Neat and tidy, with an impressive ability to process complex data fast.

As is often the case in conservation this technology has been developed for and embraced by other industries requiring ‘close scrutiny and exacting quality control’ such as precision engineering, electronics and other fast emerging fields such as nanotechnology. So, conservation sitting on these rather better funded coattails by way of mutual benefit, is no bad thing. Thank you, Formula One.

On the day, the brothers Alessandro and Marco Brecciaroli (representing Hirox) smoothly and in a charming way, guided us through the system. All too often in life it is difficult to make the full and appropriate use of a piece of equipment until one knows ‘just what it may be capable of’ and believe you me, Hirox is no slouch!

We were keen to see just how such a clever microscope could help in the field of Conservation. Could it extend the parameters of observation and perhaps more specifically, enhance our understanding. Quite possibly, and as such, this was an opportunity too good to miss.

Several of us brought museum objects with us on the day, mostly small and necessarily portable by way of putting Hirox through its paces – real objects under real scrutiny.

These included an early stained glass fragment, a painted swatch of powdery blue pigment, an intriguing small Egyptian coffin, a pre prepared pigment cross section cast in resin and a surface detail from a rare 19th century French watercolour painting.

Early stained glass fragment

      Post medieval stained glass panel (4230a Department of Applied Arts)
     A studio photograph using a conventional camera

Hirox got up close and personal and the revelations, to say the very least, were impressive.

 

In the detail above, courtesy of Hirox, we see the black tracing line,  subsequent coating of blue enamel and the surface disruption to the glass below. 

The glass surface is mildly scratched, it contains inclusions of sand (most probably silicate not fully melted during the original glass making process) and has a number of small ‘alluring air bubbles’, held captive since the middle of the seventeenth century!

The decorative element is now cracked and there are several small losses. As such, this particular artefact is somewhat at risk from further flaking.

Key features of Hirox

-Wonderful graphic quality, breath-taking magnification and the ability to capture and merge multiple images and/or create videos. And if that were not enough Hirox can be fitted with an endoscope enabling the investigation inside of an object.

-Uncompromising picture sharpness and reduced Digital Noise by way of ‘smart focusing’ and a camera that boasts the capacity to take somewhere between 50-100 frames per second, all at high resolution (1920 x 1200 pixel).

-Lighting is versatile, delivered by Light Emitting Diodes (LEDs) at a colour temperature of 5700 Kelvin. Various options include: Reflected, Transmitted, Bright Field / Dark Field and Polarization. Lighting with an Ultra Violet spectral range of 200-400 nanometres is also available if required. It would be prudent to check on both the emitted and cumulative light levels in particular and with regard any potentially light sensitive items.

-A broad range of high quality lenses are available anywhere from 1:1 to a staggering 10,000 x and numerous variant thereof. The changing of lenses appeared quick and easy by way of a bayonet fitting.

 

What soon became clear is that the examination of a small sample size and/or object was somewhat easier. For larger items one would require more careful planning and adequate space in order to engage the services of a bespoke and importantly ‘stable jig’.

Another option includes the use of a portable contact hand held lens.

Painted swatch of powdery blue pigment

Something as simple as the inclusion of a scale, seen here below in ‘microns’, is especially useful whether making a passing assessment or perhaps more so, by way of any future comparison.

The above image illustrates a powdery blue pigment part coated with a white waxy Cyclododecane1 consolidant –  in this case applied via an aerosol and now part sublimated  (evaporated).

Small Egyptian coffin

c. 600 BC / before the Common Era

The coffin surface is heavily deteriorated leaving very little of the original decoration and as such, one is left searching for clues. Hirox affords a different viewpoint and to some extent ‘a journey into the unknown’.

A small Egyptian wooden Coffin (E.43. 1907 Department of Antiquities)
44 cm (L), 13 cm (W), 14 cm (D)

Video footage across the coffin surface

The pigment trace seen in this short video is Egyptian Blue2. The remnant is trapped in one of the cracks of the coffin’s surface and although not wholly surprising it does indicate that the entire ‘wig decoration’ would have originally been painted in blue. This sort of information not only helps in our understanding of the object but it also allows for a far more accurate interpretation.

Pigment cross section

An example of a ‘stitched image’ captured by Hirox

Calcium ground      Egyptian Blue pigment           Varnish layer

Cross section of a paint sample containing Egyptian Blue (in this case a minute pigment sample was cast in resin and polished, prior to viewing).

19th century French watercolour

France, Normandy to be precise. The handy work of just who ?

This rare artwork will be on display at the Fitzwilliam Museum in the autumn of 2017 in what promises to be an exquisite show. The maker will be revealed and much more besides.

A gum glaze over watercolour         Surface abrasion

A close surface detail of a watercolour painting showing assorted fingerprints and other interesting information

3 dimensional modelling

Art meets science and maths, ooh and some pretty impressive graphics.

Real time measurements including length, angle and the surface area can be captured detailing the terrain and presented various styles. For obvious reasons, this sort of data could prove invaluable by way of comparison should the need arise, post loan or perhaps, assisting with an on going object ‘condition appraisal’.

3D Modelling of the powdery blue pigment part surface coated with Cyclododecane wax (see the earlier image of the same by way of comparison)

Like so many things in life, in order to capitalize on any investment (prices start from around £60,000 at the time of writing) one would have to give Hirox time and with that time one could reap bountiful rewards.

As such, I remain hopeful this Christmas!

 

For more information visit:

www.hirox.com

Alex Brecciaroli, Sales & Technical UK

alex@sharedlabseurope.com

www.sharedlabseurope.com

 

Thanks go to Alessandro and Marco Brecciaroli for their captivating  introduction to this impressive piece of equipment and also, to my many ‘kind and resourceful’ museum colleagues.