Collection Care blog

Did you know that conservators often wash paper?

When paper is badly degraded, and especially when there has been mould damage as with the document below, it often needs to be washed. Washing paper helps to remove acidic degradation products and reforms the hydrogen bonds in the paper structure, making it stronger.

Fig 1: Additional MS 70282. Prior to its acquisition by the British Museum this manuscript was water damaged and became mouldy. Although the mould spores are no longer active, the damage remains. The mould has eaten away at the paper, making the fibres soft and fragile. This manuscript is written using iron gall ink, which presents its own unique problems for the conservator.

Iron gall ink

Iron gall ink was the primary ink used in Europe from the middle-ages right into the 19th and even 20th centuries. It was often homemade and there is a huge variation in recipe, but its principal ingredients are tannins (usually extracted from oak galls), iron sulphate (also known as vitriol), and water. The different recipes result in inks with different levels of chemical stability, but in most cases there will be an excess of sulphuric acid and free iron (II) ions present, which result in a degradation phenomenon known as ink corrosion. Documents written using iron gall ink are very vulnerable to moisture, which can accelerate the degradation process.

In the case of Additional MS 70282 we have a manuscript which, after treatment to remove the inactive mould spores, needs to be washed in order to remove degradation products and strengthen the paper structure, but it is written using iron gall ink, which should not be exposed to excess moisture as this will accelerate its degradation. So what do we do?

Conservation options for iron gall ink

In 1995 a new treatment for iron gall ink was proposed by senior conservation scientist/ chemist J.G. Neevel at the Central Research Laboratory for Objects of Art and Science (CL) in Amsterdam. Known as the Calcium Phytate Treatment, it uses a solution of calcium phytate in partnership with a de-acidification wash in a solution of calcium bicarbonate and is designed to both remove excess sulphuric acid present in the ink and to chemically complex the free iron (II) ions, thus preventing further degradation.

Calcium Phytate Treatment

The first step is to wash the folios in a bath of reverse osmosis water until no visible degradation products (which cause the water to discolour as they wash out) remain. It may be necessary to change the water a number of times.

Fig 2: This fragile folio has been sandwiched between two sheets of archival polyester film and spot-welded before washing to ensure that fragile and mould damaged areas are not distorted and to prevent the loss of small fragments during the treatment.		Fig 3: A sheet of plexi-glass placed at the bottom of the wash bath provides a rigid support for the fragile sheets when they are being moved.
Fig 4: The rigid support can be tilted in order for the water to drain away, taking the degradation products with it. Additional support is provided by sheets of Bondina®, a non-woven polyester fabric which has a smooth surface and will not stick to the manuscript folios.		Fig 5: The folios are then placed in the calcium phytate solution, which will complex the free iron ions and prevent further degradation of the iron gall ink.

After immersion in the calcium phytate solution, the folios are washed again in a de-acidification bath, which contains calcium bicarbonate. This alkaline-reserve will remain in the paper after the treatment and help to neutralise acidity caused by the natural ageing of the paper and the ink.

Fig 6: After wet treatment, the sheets are laid out on Bondina® and blotting paper on a drying rack and allowed to air dry before they are repaired.

Although washing will reform the hydrogen bonds and make the paper stronger, repairs are still needed to support tears and infill missing areas. The most fragile folios, such as the mould damaged folio shown in Fig 1, will need to be fully lined with thin Japanese tissue. Japanese papers have very long fibres which make them ideal as conservation repair papers.

Lining and repair

Wheat starch paste, which has been thinned to the consistency of double cream, is first brushed out onto a sheet of Bondina^® using a Japanese brush.

Fig 7: A thin sheet of Japanese tissue is placed onto the pasted Bondina®, holding it by diagonally opposite corners to prevent creasing.		Fig 8: The tissue is then pasted out in the same way, ensuring an even coverage.
The folio to be lined is then humidified on a sheet of Bondina® and all the tears and small fragments are unfolded and aligned.
Figs 9 & 10: Carefully holding the corners of the Bondina®, the humidified folio is turned over and lowered directly onto the pasted lining tissue.

It is then brushed-out through the Bondina^® using a Japanese brush to remove any air bubbles and ensure a strong bond. After air-drying, the missing areas are in-filled with a matching Japanese paper, before the other side is lined in the same way.

Figs 11 & 12: Details of two mould damaged folios after conservation treatment.

After all repairs were completed the folios were tipped to guards of archival paper, collated, and given a new binding to protect them.

This manuscript is part of the Portland Papers, which were originally housed at Welbeck Abbey and deposited in the British Museum between 1947-1967 by His Grace, the seventh Duke of Portland as 'The Portland Loan.' They were allocated to the British Library in 1987, having been accepted by the government in lieu of Capital Transfer Tax.

The conserved manuscript can now safely be consulted by readers in the Library's Manuscripts Reading Room.

Francesca Whymark

This manuscript was conserved by Timothy Nason and Gayle Whitby and bound by Douglas Mitchell.

We recently took you Under the microscope with the Lindisfarne Gospels in a previous post and shared some incredible images of medieval artistry. The four gospels are introduced by an illumination of the saint, a carpet page, and a major initial opening a folio of decorated text. We asked you to identify the folio from one of our zoomed in images. Did you figure it out..?

As you can see below, it is part of folio 2v, the carpet page of St Jerome! 

Carpet page of St Jerome ff 2v

   
 Figure 1: The carpet page of St Jerome (folio 2v)

Figure 2: The image in question showing the step and key pattern in the cross panels. This region has been magnified by x50.

Carpet pages typically occur at the beginning of a gospel in illuminated manuscripts and exhibit geometric and colourful designs that consume the entire folio. They are referred to as carpet pages due to their resemblance to oriental rugs or prayer mats. Prayer mats were used to prepare worshippers for prayer and the carpet pages in the Lindisfarne Gospels serve a similar function in preparing readers for the Gospel message. The carpet pages feature a cross set against a background of highly ordered ornamentation. Each carpet page in the Lindisfarne Gospels contains a different form of cross representing different church traditions.

Folio 2v is dominated by an interlace motif controlled by the eight-ribbon knot with cruciform breaks pattern. As observed in our image they surround a cross consisting of panels filled with step and key patterns. The folio is borded by ribbon birds and dog heads.

Carpet pages were influenced by early Coptic manuscripts and contain ornamentation with similar motifs found on contemporary metalwork and jewellery.

Christina Duffy, Imaging Scientist

The work of our Collection Care team is going to feature on a new major television series airing on BBC Four. King Alfred and the Anglo-Saxons will examine the careers of King Alfred the Great, the Lady Æthelflæd and King Athelstan in a three part series starting on Tuesday, 6 August (21:00-22:00). Some of the archival material consulted for the series is from the burnt Cotton collection and was severely damaged by fire in the 18th century at Ashburnham House. Our conservators, scientists and curators will be featured handling and caring for the vulnerable material in all three episodes, while being interviewed by presenter and historian Michael Woods. The extraordinary tale of King Alfred is almost surpassed by the fascinating history of the ill-fated Cotton manuscripts.

MayaVision presents King Alfred and the Anglo-Saxons on BBC Four on Tuesday, 6, 13 and 20 August (21:00-22:00) featuring the British Library’s Collection Care team

The Cotton Collection

Two of the manuscripts consulted during filming were Cotton MS Otho B. IX, a late 9th- or early 10th-century gospel book which came into the possession of King Athelstan, and Cotton MS Otho A. VI, the only surviving copy of Alfred the Great’s Old English prose and verse translation of Boethius’s Consolation of Philosophy. The Cotton collection refers to the library assembled by Sir Robert Cotton (1571-1631) which was presented to the British nation by his Grandson Sir John Cotton around 1700. It contains some of the most well-known treasures of the British Library including the Lindisfarne Gospels (Cotton MS Nero D. IV), Magna Carta: Exemplification of 1215 (Cotton MS Augustus II. 106) and Beowulf (Cotton MS Vitellius A. XV). Manuscripts were originally housed by Sir Robert Cotton in large presses surmounted by busts of the Twelve Caesars and two Imperial Ladies, and labelled according to their position (for example Cotton Otho A. VI was under the bust of Otho, top shelf (A), and six over). This arrangement has been incorporated into modern shelfmarks at the British Library. It was described as ‘the most important collection of manuscripts ever assembled in Britain by a private individual.’ Suddenly, the unthinkable occurred.

A fire breaks out

On 23 October 1731 a great fire broke out where the Cotton manuscripts were being temporarily held at Ashburnham House, Westminster. About a quarter of the collection was affected. The librarian at Ashburnham House Dr Bentley is recorded to have leapt from a window to escape the fire with the 5th-century Codex Alexandrinus (MS Royal 1. D. V-VIII; one of three of the earliest manuscripts of the Bible) under one arm. Thanks to Bentley’s agility you can today view the manuscript online in its fireproof digitised form. The fire consumed almost the entire printed book collection and some of the manuscripts. Although only 13 entire manuscripts perished, there was significant damage to many which lost important articles or remained only as charred fragments.

A box of charred fragments collected from the Ashburnham House fire in 1731. The many cinder-like fragments and burnt lumps of parchment were bundled into drawers and flimsy boxes later causing much confusion as to their origin

The damage was utterly devastating. A black edge bead had formed on the manuscript edges, most often consisting of a brownish congealed gelatine and carbon particulates. Gelatine is the end product of the sudden degradation of the parchment collagen and occurs when the long fibres under tension break apart. When cooled the parchment became very brittle and any subsequent handling resulted in serious textual loss. The heat not only damaged the text but left vulnerable wax seals as melted shapeless globules bereft of their intricate design.

A fragment of warped parchment from the burnt Cotton collection at 20x magnification. The iron gall ink follows the path of the parchment making it difficult to read

As is often the case in fires, much of the damage was caused by the water used to extinguish the flames. Damp parchment and paper manuscripts were at risk of developing mould and urgently required drying.

Early conservation work

In the aftermath of the fire emergency conservation work resulted in many manuscripts being broken up and rebound. Carbonised bindings were removed and the burnt parchment manuscripts were carefully opened. Some of the parchment manuscripts were dried by lying flat out. In the rush of the rescue work many of the leaves were assembled in the wrong order, permanently disrupting the collation of volumes.

A renewed effort at restoration

The Cotton collection made its way to the British Museum in 1753, but it wasn’t until 1837 when Sir Frederic Madden was appointed Keeper of Manuscripts that further work was done. The burnt manuscripts were divided into classes depending on the severity of the damage, and a plan was put in place for their restoration. Expertise was sought from Henry Gough who had undertaken repair work of damaged manuscripts in the Bodleian and other College Libraries in Oxford. Solutions of ethanol and water were reported to have been used to soften the manuscripts in order to wash individual leaves. Tiny incisions were made between the columns and the lines of writing to allow room for expansion of the most shrivelled part of parchment contracted by the flames. Many of the Cotton manuscripts thought to have been lost were identified, flattened, inlaid, collated and bound.

The inlaid leaves of Cotton MS Vitellius B. IV. Since the parchment is sensitive to humidity changes it can pull on the paper frame causing cockling

Cockled paper in Cotton MS Vitellius A. VIII distorts the bindings making volumes difficult to close

The remaining loose fragments were flattened, some identified and most of those inlaid. Inlays were made by tracing out the shape of the parchment leaves on construction paper. These pencil marks are still visible and you may have noticed them on some of our Digitised Manuscripts. The centre of the construction paper was cut out a few millimetres inside the pencil lines to leave a frame. Paste was applied behind the frame and the loose leaf was then secured in place, sometimes obscuring regions of writing. The paste often left stains that later became brittle.

Cotton MS Otho A. VI folio 32r. Incisions between lines of writing are observed on the right hand side of the parchment to allow for expansion. Pencil lines are visible around the edges where the inlay was traced and cut out. The cockled centre and shrunken edges reflect a temperature gradient across the original book block, which remained cooler nearer the centre

The entire process was complete in 1856. Although the inlaying has been much criticised it provided much-needed protection against handling as some of the leaves had a tendency to erode. Many more fragments may have been entirely lost had they not been treated at all.

Another fire!

On 10 July 1865 Madden received some horrifying news: another fire had broken out and the manuscripts were again in jeopardy. He was horrified. A charcoal brazier in the finishing room at the bindery had caused the blaze resulting in severe damage to the manuscripts that had been left out to work on. Fortunately, the majority of the manuscripts were locked away in an iron safe, but it was little consolation for Madden’s tireless efforts. Madden kept a detailed record of his work as Keeper which is today held in the British Library. A late 9th-century copy of King Alfred’s Old English translation of Gregory the Great’s Pastoral Care (Cotton MS Tiberius B. XI) was lost and according to Madden’s records: “…it lay on a board immediately above the bin of charcoal, and a slate slab was placed above it. The slate flew into fragments from the heat, and the MS. (a good thick folio written on vellum, bound in russia) must have fallen into the midst of the burning charcoal.”

Madden retired in 1866 somewhat bitter about the lack of recognition he received for his conservation efforts. Much of the documentation regarding his work was unknown to the public until 1981 when they were incorporated from the Departmental Archives into the Additional Manuscripts. The story of the Cotton manuscripts is a fascinating one and you can read more detail in this essay by Andrew Prescott.

Cared for at the BL

More than 1,400 manuscripts and over 1,500 charters and seals comprise the Cotton collection at the British Library ranging in date from the 4th – 17th centuries. Madden would be pleased to know that we now have low-oxygen storage facilities to prevent any more fires from breaking out! Collection Care is using new imaging technologies such as multispectral imaging to recover lost information and protect these valuable fragments from misuse. Much work has recently been carried out on the burnt Cotton collections by our parchment specialist Mariluz Beltran de Guevara. Even now more fragments are being identified. For more examples of burnt material at the British library read our Conservation Officer Ann Tomalak’s post in the Medieval Manuscript’s blog.

Tune in to BBC Four this month to see the manuscripts in action. Understanding the history of our collections is crucial for understanding the care required to treat them.

Christina Duffy (@DuffyChristina)

Imaging Scientist

Six of the British Library’s Anglo-Saxon and medieval manuscripts are currently on loan to Palace Green Library  in Durham City for their summer exhibition. The work of our Conservation Science and Research team was recently highlighted in a post on the Lindisfarne Gospels Durham website. Microscopic analysis is often used by our team as part of the condition assessment of fragile collection items.

Patience is a virtue

Tiny drops of red/orange colour produced from toasted lead are found throughout the Lindisfarne Gospels creating outlines, patterns and backgrounds for many of the folios. This type of decoration often appears in early Irish manuscripts. In Figure 1 a section of the initial page of the Gospel of St Luke on folio 139r was analysed with image processing software to determine the number of dots. 1,939 dots were found in just this one example area. It is no wonder that the manuscript’s production was costly both in time and materials!

Left: Folio 139r displays the initial page of the Gospel of St Luke.  Right: An image of one area containing the letters niam from the Latin Quoniam (Quoniam quidem multi conati sunt ordinare narrationem) was analysed to count the number of dots

The Lindisfarne Gospels are particularly remarkable given that the entire manuscript is thought to have been the work of just one man. A century after the production of the manuscript a note was added at the end attributing the work to a monk called Eadfrith who was the Bishop of Lindisfarne between 698 and 721.

Craquelure and crackling

Eadfrith's patience wasn't the only thing at risk of cracking up. Craquelure is a network of tiny cracks caused by pigment shrinking due to age. It is often seen on paintings where large grids of cracks are visible across the surface. When the disruption consists of perpendicular lines it is referred to as crackling, and the potential for formation is exacerbated when the pigment has been thickly applied. Crackling is seen in many of the pigments in the Lindisfarne Gospels, even in the tiny red dots used for decoration.

 Figure 2: Increasing views of folio 5v showing red/orange dot detail. The Lindisfarne Gospels are written in Latin but an Anglo-Saxon translation was added between the lines in red ink when it was owned by Aldred, Provost of Chester-le-Street in the 10th century

Folio 5v at 50x magnification.

Folio 5v 150x magnification. Tiny red/orange dots from toasted lead fill backgrounds of iron gall ink letters. Crackling is observed on the dots

 

Pigments

The exquisite suite of colours used in the manuscript was produced by Eadfrith using animal, vegetable and mineral pigments from both local and imported sources. A beaten egg-white preparation called glair was used as an adhesive and mixed with pigments. The black ink used for the main text of the gospel is iron gall ink made from oak-galls and iron salts, while a black pigment called lamp black containing particles of carbon was used in the illuminations. Green colours were produced using either verdigris, which is made by suspending copper over vinegar, or vergaut made by mixing blue and yellow pigments. The top of the decorated initial in Figure 4 is coloured with a yellow pigment called orpiment which contains arsenic trisulfide (As₂S₃).       

Figure 4:  Above: Folio 44v displays Latin text with decorated initials.

Folio 44v at 50x magnification. This letter is filled with a green pigment of either verdigris or vergaut. The top of the initial is coloured with a yellow pigment called orpiment. Crackling is visible on both green and yellow pigments

The chemical composition of the pigment contributes to the onset and degree of crackling. In the Lindisfarne Gospels, yellow orpiment shows the greatest degree of craquelure.

Figure 5:  Above Left: A partial image of folio 51v which contains mostly Latin text with some decorated initials.  Above Right: A decorated initial at 20x magnification.  Below: Folio 51v at 50x magnification. Red/orange lead dots border this initial which is filled with orpiment showing signs of craquelure

The entirety of the Lindifarne Gospels is digitised and available online at the British Library’s Digitised Manuscripts website, as well as being available on the Library’s interactive Turning the Pages^TM feature. It is well worth spending some time looking through the various illuminations. Figure 6 shows a region of the manuscript at 50x magnification. See if you can identify the folio (the answer is posted here)!

Figure 6: A 50x magnification image of a region on one of the carpet pages in the Lindisfarne Gospels.

 

The Lindisfarne Gospels is an incredible human achievement and a truly spectacular example of medieval artistry. The exhibition at Palace Green library runs from 1 July to 30 September 2013. If you are in the Durham area it is well worth a visit.

Christina Duffy (@DuffyChristina)

Imaging Scientist

Recently, a memoir and correspondence relating to a 20th century poet have come to Conservation to be prepared for digitisation. Some five years ago, we conserved another group of his letters. Superficially, the work was much the same for both: clean, repair and rehouse. But for the first batch the letters were carefully removed from an old guardbook and a new half-leather album made for them. Every item was cleaned, flattened where necessary, tears were repaired and losses infilled. Then each was hinged to a full support sheet, with compensation guards to accommodate the thickness and prevent the album from gaping. The work took 565 hours in all.

By contrast, treatment of the second batch of letters and the memoir was minimal: only essential dry cleaning and flattening plus some minor paper repairs, before they were rehoused as loose sheets in phase boxes; all completed within the estimated time of 20.5 hours.

Figure 1: A small edge tear can become more serious, if not repaired quickly. Here, a fragment of the text has been lost. (Add Ms 5873 f.105) 

What has changed? We are not cutting corners in conservation these days, but are responding to a digital revolution within the British Library, itself reflecting the needs and expectations of our users. Just five years ago, we accepted that famous poets were of great interest to our users. We knew their letters were, and (we thought) would continue to be, issued frequently in the Reading Room, and so we treated and rehoused them accordingly. The new guardbook provided greater protection and security, and the letters could be read with less handling.

Figure 2: Friable ink: a little more of the text is lost every time the manuscript is opened. Digitisation offers the “best available” reading to all, whilst the manuscript itself can be restricted until the ink has been treated. (Harley 5620)

The drive for digitisation had already begun, but we hadn’t then understood the implications for the use, and thus for the conservation, of collection items. Today, researchers (and the public in general) expect to have access to the collections via their laptops, tablets and smartphones, to share images and comments through social media and even to annotate our catalogues. The Library has long been willing to provide photographs or microfilm of collection items at a price; the demand now is for high quality digital images and free access. Digitisation projects are proliferating across the library.

Figure 3: The Henry Prayer Roll: Pigment losses at folds and creases caused by tight rolling and poor handling. The roll has now been rehoused on a wide core and is stored in optimum conditions, so we do not expect further losses. (Add Ms 88929)

Users of our digitised material find access easy from anywhere in the world and at any time of day or night. They also benefit from enhancements such as the ability to zoom in and discover details not visible to the naked eye. Frail material that is normally restricted - rarely issued in the Reading Rooms, and only viewed under supervision – is freely available on our website. So are treasures that can only be viewed as a single opening under low lighting levels in our exhibition galleries, some further enhanced by Turning the Pages^TM technology. A digitised text is never unavailable because another reader is using it.

Figure 4: A Greek Menologion damaged throughout by damp, mould and rodents. Full conservation is a major undertaking, but we can make the manuscript available more quickly by digitising it. A conservator works with the photographer, doing all the handling, to ensure there are no further losses or damage. (Add Ms 82957 f.3)

The collections benefit too. Items that get less physical handling are less likely to get damaged. They can stay in optimum storage conditions, rather than travelling to the Reading Rooms, and so deterioration is slowed. This is allowing us to rethink conservation requirements. Instead of heavy repairs to withstand frequent handling, we can now choose minimal intervention, just sufficient to allow material to be imaged safely. In some cases, we even send a conservator to help with the set-up and handling in imaging, as a less costly alternative to full conservation treatment.

Figure 5: A damaged spine reveals hidden evidence. The spine linings for this manuscript on paper are strips cut from an earlier manuscript on parchment, overlapping at the centre spine. It was common to recycle materials in this way. It is also possible to see the original double sewing supports and the sewing pattern. (Add Ms 78328)

The less we need to intervene, the more we can preserve original materials and structures – and this is becoming more important to researchers. Historically, rebinding was common to protect and preserve the text which was all-important, but now we understand that early binding techniques, indications of parchment or paper preparation, the composition of inks and pigments and much else are a reserve of material culture evidence, giving non-verbal insights into the past. If digitisation means items are issued much more rarely in future, there is less reason to replace weak original materials, or repair damage that is unlikely to get worse in storage; especially where, say, interesting binding structures can be glimpsed through losses in the covering. Rather than lavish six months’ conservation on a single item, we can apply our resources more intelligently, thinking more in terms of preservation and improving long-term storage conditions for whole collections. An example of this is the new low-oxygen newspaper storage facility at Boston Spa.

All in all, digitisation benefits us all; users, Collection Care and the collections themselves.

Ann Tomalak

Our Conservation Science and Research team often receives requests for revealing hidden information. The manifestation of hidden information can be intentional (such as erasures and substitutions obscuring underlying text, e.g. Figure 1), or it can be a result of materials succumbing to the passing of time (archival degradation). Archival degradation is present in all materials due to natural aging and can be accelerated by usage, poor storage conditions, unsuitable humidity, mould, insect infestations, and physical damage such as fires or floods.

These conditions lead to typical deterioration artefacts including metal gall inks corrosion, ink diffusion and fading, seeping of ink from overleaf (bleed-through effect), blurred writings, fragmentation of ink or areas of ink loss. Attempting to capture what was originally underneath these artefacts can be very challenging. Each case is unique and it is often a combination of techniques which reveals information. One such technique used at the British Library is multispectral imaging.

Figure 1: An obscured inscription found on an incunabulum (IB.49437, Cordiale quattuor novissimorum [French] Les quattres choses derrenieres, translated by Jean Miélot)

Multispectral imaging is a non-invasive, non-destructive form of computational photography which can enhance difficult-to-read text using an extended light spectrum. The visible spectrum is the range of light wavelengths that can be detected by the human eye, and is what we often associate with the colours of the rainbow. Radiation either side of the visible region cannot be observed with the human eye, but can be detected in other ways. Image capture in multispectral imaging ranges from 420-1000 nm going beyond the visible spectrum into the ultra-violet (UV) where faded iron gall ink is enhanced, and into the infra-red (IR) where carbon underwriting and substitutions are revealed.

Faded text

Multispectral imaging was recently used to help catalogue an analogue tape from The Alan Cooban collection (C1398) for the Sound Archive. Mr Cooban recorded BBC transmissions off-air onto open reel tape from approximately 1957 to 1980. His metadata and labelling is excellent, for the most part. However, the very early tapes were housed in tin containers and in many cases the writing has worn away. Multispectral imaging was used on one such reel whose number was barely visible on the metal container it was housed in (Figure 2). A false colour image (which consists of an image combining green, blue and 800 nm images) was processed to reveal a possible number 34 or 37. Through catalogue cross-referencing and comparison with other tape labels it was confirmed as 34. The Alan Cooban collection comprises approximately 1900 tapes, and the Sound Archive has been transferring them for the past year and a half. They expect to finish this September.

Figure 2: A faded label on an analogue reel from the Alan Cooban collection (C1398) is enhanced with false colour multispectral imaging

Palimpsests

A palimpsest is a reused writing surface from which the original text has been scraped and washed away to allow the surface to be used again. Many palimpsests are found on parchment which was sometimes recycled due to its high cost and labour intensive production. In the case of medieval codices the original text is often found to be running perpendicular to the overlaid ink due to the manner in which the parchment was folded and cut for reuse.

Or. 6581 shown in Figure 3 consists of three single leaf palimpsest fragments from the Genizeh at Cairo, housed under glass. Hebrew commentaries of the 11th or 12th century are written over the original text. The largest of the fragments (shown in the centre and right of Figure 3) has old Palestinian Syriac under the Hebrew, rather than Georgian, as is found underlying text in the central fragment (reference: George Margoliouth's Catalogue of the Hebrew and Samaritan Manuscripts in the British Museum, printed in 3 vols. 1899 [reprinted in 1965]; v. 3, p. 579, and Oliver Wardrop’s A Catalogue of Georgian Manuscripts in the British Museum, appendix to Frederick Cornwallis Conybreare’s A Catalogue of the  Armenian Manuscripts in the British Museum, 1913, p406.).

The fragments were recently examined using multispectral imaging to generate new images which may aid in the reunification of neighbouring fragments. The style of the writing in the largest fragment resembles that of the fragment T-S. 12. 183 of the Cambridge University Library, with both potentially belonging to the same MS of the Bible.

Figure 3: The three palimpsest fragments of Or. 6581 housed under glass. Multispectral imaging shows the largest fragment observed in the infrared (centre) and in the ultraviolet (right) part of the spectrum

Palimpsests are easier to extract and interpret using multispectral imaging. Images of all three fragments in the infrared, visible and ultraviolet regions of the spectrum were assigned to the colours red, green and blue to create a composite image shown in Figure 4, where palimpsest detail is enhanced. 

Figure 4: Composite images of Or. 6581 palimpsest fragments showing improved detail

Multispectral imaging has many applications across the British Library and has helped in imaging watermarks, differentiating pigments and uncovering signatures. It has proven to be an excellent tool for information recovery and, combined with other techniques, enhances the scholarly understanding of many of our collection items.

Christina Duffy