British Museum blog

Scientific investigation of the Norwich shroud

Janet Ambers, Scientist, British Museum

Research Fellow Emma Passmore taking UV images of the shroud. © Norwich Castle Museum and Art Gallery / Trustees of the British Museum

Research Fellow Emma Passmore taking UV images of the shroud. © Norwich Castle Museum and Art Gallery / Trustees of the British Museum

    This is the latest in a series of posts about the unfolding of the Norwich shroud, a joint project between the British Museum and Norwich Castle Museum and Art Gallery

With the shroud unfolded for the first time (although still in need of much conservation attention) David Saunders, Keeper of Conservation and Scientific Research, Emma Passmore, Mellon Research Fellow, Caroline Cartwright, scientist, and I made our first visit to see what had been revealed on the inner surface.

David has a longstanding interest in the use of imaging techniques to enhance and investigate painted surfaces, and our main objective was to examine areas where text has been applied.

Using specialist cameras, we took both infrared and ultraviolet images of the shroud. Infrared reflectography is often employed in research into paintings to reveal initial sketches under the final images. For the shroud, it will make the black text clearer. This will help John Taylor with his interpretation of the hieroglyphs while the conservators continue to treat the shroud, and also allow the hieroglyphs to be published clearly for international scholars.

Imaging with ultraviolet light may help to show surface coatings and stains. Both of these approaches are very useful for objects like this as they provide information without the need for sampling, or indeed for any contact with the surface at all.

Caroline Cartwright, who specialises in fibre identification (amongst other things), took tiny samples of the linen ground (approximately two to three millimetres long) both with and without pigment.

Examining them under the scanning electron microscope (SEM) allowed her to positively identify the fibres as linen, and give the conservators information about their construction and condition.

SEM image of a fragment of the Norwich shroud. © Norwich Castle Museum and Art Gallery / Trustees of the British Museum

SEM image of a fragment of the Norwich shroud. © Norwich Castle Museum and Art Gallery / Trustees of the British Museum

The images here clearly show the weave of the textile, the twist direction of the fibres, and pigment sitting on the surface of the linen fibres (which appears white under the SEM). It also shows how few breaks there are in each fibre, confirming their good condition, and how surprisingly clean they are, suggesting the shroud may have been kept mostly in a folded state, and/or not extensively disturbed, be it by repeated opening and folding, handling, study or display.

SEM image of linen fibres from the Norwich shroud. The lack of tears in the individual fibres confirms what good condition they are in. © Norwich Castle Museum and Art Gallery / Trustees of the British Museum

SEM image of linen fibres from the Norwich shroud. The lack of tears in the individual fibres confirms what good condition they are in. © Norwich Castle Museum and Art Gallery / Trustees of the British Museum

My main role is to identify the pigments used. To enable me to do this Melina Plottu, our textile conservation intern from France, collected samples of the various pigments. She removed tiny pieces of single fibres with traces of colour on and placed them between two slides. I took these back to our laboratories and examined them under the microscope of a Raman spectrometer.

Textile conservation intern Melina Plottu carefully places a sample of linen with traces of colour on it into a glass vial held by scientist Janet Ambers.  © Norwich Castle Museum and Art Gallery / Trustees of the British Museum

Textile conservation intern Melina Plottu carefully places a sample of linen with traces of colour on it into a glass vial held by scientist Janet Ambers. © Norwich Castle Museum and Art Gallery / Trustees of the British Museum

This equipment uses changes in the wavelength of a laser beam shone on to a material to provide an absolute identification.

Raman showed that both the light and the dark black pigments are based on carbon. There is a possibility that crushed charcoal was used for this, but the most common Egyptian black ink is known to have been produced using soot (sometimes called carbon black in the art world).

Why some areas of black text on the shroud are much lighter than others is not yet clear. The colour in the red ink comes from hematite, an iron oxide. This is responsible for the colour of red ochre, a form of red coloured earth extensively found throughout Egypt and frequently used as a pigment in Egyptian art.

Taking a sample from the shroud. © Norwich Castle Museum and Art Gallery / Trustees of the British Museum

Taking a sample from the shroud. © Norwich Castle Museum and Art Gallery / Trustees of the British Museum

Melina and Monique Pullan, the textile conservator leading the conservation, have also found a single area of white pigment, used around the area of a cartouche in the centre of the shroud. This proved to be gypsum, a white mineral common in Egypt.

Wall painting from the eighteenth dynasty tomb chapel of Nebamun. The skin of the central seated figure and male slave are coloured with red ochre © Trustees of the British Museum

Wall painting from the eighteenth dynasty tomb chapel of Nebamun. The skin of the central seated figure and male slave are coloured with red ochre © Trustees of the British Museum

The conservators were reassured to know it wasn’t huntite, another white mineral sometimes used as a pigment in Egypt – its sensitivity to moisture would have precluded many of the water based treatments used to relax and realign fragile fibres.

Filed under: Conservation, Norwich shroud

One Response - Comments are closed.

  1. Dan says:

    I love the electron microscope pictures!

    Like

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 9,419 other followers

Categories

Follow @britishmuseum on Twitter

British Museum on Instagram

Room 8, Nimrud, is the next #MuseumOfTheFuture gallery in our series. It contains stone reliefs from Neo-Assyrian King Ashurnasirpal II’s magnificent Northwest Palace at Nimrud and two large Assyrian winged human-headed lions. The next gallery in our #MuseumOfTheFuture series is Room 7. It features a series of remarkable carved stone panels from the interior decoration of the Northwest Palace of the Neo-Assyrian King Ashurnasirpal II (883–859 BC). The panels depict the king and his subjects engaged in a variety of activities. Ashurnasirpal is shown leading military campaigns against his enemies, engaging in ritual scenes with protective demons and hunting, a royal sport in ancient Mesopotamia.
#museum #london #gallery Room 6, Assyrian sculpture and Balawat Gates, is the next gallery in our #MuseumOfTheFuture series. This room contains large stone sculptures and reliefs which were striking features of the palaces and temples of ancient Assyria (modern northern Iraq). Also in the gallery are two colossal winged human-headed lions, which flanked an entrance to the royal palace of King Ashurnasirpal II (883–859 BC) at Nimrud and replicas of the huge bronze gates of Shalmaneser III (858–824 BC) from Balawat. King of Persia Cyrus the Great entered #Babylon #onthisday in 539 BC. This iconic clay cylinder, known as the Cyrus Cylinder, is inscribed in Babylonian cuneiform with an account by Cyrus of his conquest of Babylon in 539 BC and the capture of Nabonidus, the last Babylonian king. 
The cylinder has sometimes been described as the 'first charter of human rights', as it describes measures of relief Cyrus brought to the inhabitants of the city after its capture. However it in fact reflects a long tradition in Mesopotamia where, from as early as the third millennium BC, kings began their reigns with declarations of reforms. 
#history #art Experience the pleasures of the early Ming court in an evening of performance, demonstrations, talks and workshops on Friday 14 November. Free, just drop in #Ming50Years 
#event #free #china #art #onthisday in 1420: Beijing is officially designated the principal capital of the #Ming empire. Find out more about the Forbidden City and this beautiful hanging scroll in a new tumblr post at britishmuseum.tumblr.com #Ming50Years
#China #art #history #Beijing
Follow

Get every new post delivered to your Inbox.

Join 9,419 other followers

%d bloggers like this: