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

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Most Greek sculpture that survives from antiquity is carved from white marble, of which the Mediterranean has many natural sources. A relationship has often been assumed between the pure white of freshly cut marble and the idealism of Greek art. In fact, the opposite is true. Colour was intrinsic to ancient ideas of beauty. For centuries this has been a subject of fascination and controversy. The great Italian Renaissance sculptor Michelangelo revived the Greek idea of the human body but denied the use of colour. This was partly due to negative associations with the painted saints of the medieval period. During the European Enlightenment of the 1750s onwards, and increasingly into our own time, the preferred aesthetic was a truth to materials. Painting and gilding were seen as unnecessary and undesirable.

Sculpture in antiquity was often adorned not only with colour but also with different materials. The Greek marble statue of an archer reconstructed here was drilled and fitted with metal attachments. The figure originally held a bronze bow and arrow and a quiver was fixed to his left hip by a metal dowel. Individual locks of hair were made of lead. The colourful design of the man’s knitted all-in-one garment, often worn by peoples from the east, is clearly seen weathered into the marble surface under controlled lighting.

You can see this wonderful object in our exhibition #DefiningBeauty, until 5 July 2015.
#exhibition #BritishMuseum #ancientGreece #sculpture #art

Plaster cast of archer with reconstructed paint, based on a Greek original of about 490–480 BC, from the Temple of Aphaia at Aigina. Staatliche Antikensammlung und Glyptothek, Munich. Uta Uta Tjangala's masterpiece Yumari is a highlight of‪ #IndigenousAustralia, opening a week today
#exhibition #art #history #BritishMuseum #Australia #museum Hans Sloane's collection also ended up as the basis of the @natural_history_museum and the @britishlibrary!
To make more room for the increasing collections held by the British Museum, the natural history collections were moved to a new building in South Kensington in the 1880s. This eventually became the Natural History Museum. These images show some of the natural history specimens on display, including giraffes and a mastodon!
In 1997, the library departments left the Museum to be re-housed at the new British Library in St Pancras.
#history #BritishMuseum #collection #animals #books Hans Sloane's encyclopaedic collection became the cornerstone of the British Museum.
This drawer was once part of the materia medica - a sort of pharmaceutical cabinet - in the collection of Sloane. The cabinet had several drawers, each carefully constructed to keep out destructive insects. Some drawers had small compartments like this example, others contained glazed boxes with seeds, fruit, bark, roots, gums and resins inside. Each had a label written by Sloane with a catalogue number. The botanical or medicinal name of the subtance, where it came from and who collected it were then recorded in his catalogues of his collection.
As Sloane's interest in natural history grew along with his income, he was able to widen the scope of his collection from being primarily medical to being more encyclopaedic, representing the widest possible variety of substances and artefacts for his own reference and for others to consult.
© 2003 The Natural History Museum @natural_history_museum 
#history #BritishMuseum #collection #museum Our founder, Sir Hans Sloane, was born ‪#onthisday in 1660.
This engraving after a portrait  by T Murray shows him at the age of 68. The inscription at the bottom can be translated as: 'Sir Hans Sloane, baronet / Pres[ident]. of the College of Physicians of London and the Royal Society. etc.'
Sloane was born in Ireland in 1660, and trained as a doctor of medicine. At the age of 27 he went to the West Indies as personal doctor to the Governor of Jamaica and while living there he began to form his great collection of natural history specimens. For the rest of his long life he collected plants, fossils and minerals, as well as objects from ancient Rome, Egypt and Assyria. He also amassed an impressive collection of books, manuscripts, prints and drawings.
#history #BritishMuseum Leonardo da Vinci was born #onthisday in 1452. 
This study of a warrior is drawn in metalpoint, specifically silverpoint, a popular medium with Early Renaissance artists. It is most suitable for detailed and careful drawings. Metalpoint was a good method of training young apprentice artists as it required control and discipline. 
Here, the silverpoint line, which has turned grey in the atmosphere, is thin and delicate. The detail is extraordinary: the armour, the curls in his hair and the splendid elaborate helmet are even exceeded by the modelling of the man's face and the lion on his breastplate. Endless patience must have been required of the young Leonardo to produce the very fine shadows of the man's face, each a separate line.
#art #daVinci #Leonardo #history #drawing #silverpoint
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