Collection Care blog

26 posts categorized "Imaging Science"

03 June 2021

Iron gall ink on paper: Saving the words that eat themselves

Paul Garside & Zoë Miller

Iron gall ink (IGI) will be familiar to most of us as the characteristic brown ink that we associate with the authenticity and softly aged aesthetic of historic documents.  It is the most important writing and drawing ink in Western culture, initially emerging in the first centuries AD and continuing in widespread use until the 20th century.  Many thousands of examples of its use on both parchment and paper can be found in the British Library’s historic collections, ranging from Treasures and other important items, such as the Codex Sinaiticus, the Lindisfarne Gospels, Magna Carta, manuscripts penned by Henry VIII and the works of famous diarists such as John Evelyn, to more commonplace letters, notes, musical scores and records. And IGI documents will form a vital part of our forthcoming exhibition Elizabeth and Mary: Royal Cousins, Rival Queens .

Figure 1: Three sheets of paper with dark brown iron gall ink.  The ink on the opposite sides of the papers is starting to show through.

[Figure 1] An example of IGI on paper (Walpole Papers 73898).

However, IGI may damage the surface on which it is written, and paper is at particular risk, leading to characteristic haloing, fragility, fracturing and areas of loss. It has been estimated that up to 80% of European archives contain items at significant risk of this problem. The potential to cause damage has been known for a long time: in 1765 the English chemist William Lewis published a treatise on the stability of IGI, and over one hundred years ago the Vatican Library warned about the impending destruction of many precious manuscripts from the effect.  However, the ink remained popular, not least for its durability and permanence (it adheres firmly to the substrate, and resists rubbing and washing, unlike carbon inks), but also because it was easy and cheap to make, using a wide variety of historic recipes.  Most recipes are based around four principal components: gallic acid, derived from oak galls; iron(II) sulphate (often referred to as green vitriol); water or an aqueous medium; and a binding agent, such as gum Arabic.  When these ingredients are mixed, the acid and the iron sulphate react together then oxidise to form iron(III) gallate, which is strongly coloured; the ink is typically a dark slate grey when first formed, turning brown or orange as it ages.

Figure 2: A magnified image of iron gall ink on paper, lit from the back, showing dark haloing around the text and areas of loss from regions of heavy ink.

[Figure 2] The effects of IGI corrosion.

Why does this ink cause damage? There are two main, interlinked processes. Sulphuric acid is a by-product of the reaction which creates the ink, and this can lead to hydrolysis of the cellulose that forms the building blocks of paper. Excess iron(II) ions, from the initial ingredients, can also speed up the oxidative degradation of cellulose. In conjunction, these two effects are often referred to as IGI corrosion, and in extreme cases inked lines can actually crack and drop out of the paper surface. We have found that imbalanced recipes and impure ingredients can complicate the aging process and damaging properties of these inks, resulting in wide visual differences. The Instituut Collectie Nederland (ICN) has developed a four level system to categorise the damage caused by IGI , from 1 to 4 ('good' to 'very poor' condition), as shown in these examples from the BL's collection:

Figure 3: The four ICN condition levels, illustrated with examples from the British Library’s collection.

[Figure 3] The condition of IGI on paper: 1 (good condition - no/light discoluration and stable to handle); 2 (fair condition - dark discolouration around ink, with no immediate mechanical damage, but this could result from handling); 3 (poor condition - some mechanical damage around ink, and handling is likely to cause more damage); 4 (very poor condition - serious loss of substance, which will be exacerbated by handling).

Historically, treatments for paper documents suffering from IGI corrosion were much more invasive than would now be considered acceptable, including processes such as lamination, simmering or aggressive de-acidification.  Greater understanding of the material and developments in conservation science have allowed a more tailored, less invasive range of options. For some documents, aqueous treatments will be the most appropriate choice: the items are immersed in a calcium phytate solution, to bind and isolate damaging iron(II) ions, accompanied by gentle de-acidification, to remove existing acids and provide an alkaline reserve.  For other documents, low moisture repairs (using gelatine adhesive, which resists IGI attack as well as providing mechanical stabilisation) or the more conventional support of physical damage will be better choices.  The following chart gives an overview of our thought-processes when considering the best approach; we developed it to help visualise the process and explain our decision-making to colleagues.  As can be seen, we would consider a wide range of factors, including:

  • The state of the IGI and the damage it has caused, assessed using the ICN categorisation.
  • The overall condition of the item, taking into account any signs of damage to its composition or structure, the presence of vulnerable components such as water-sensitive materials, and its general stability and ease of handling.
  • Our 'risk appetite' for the item.  This represents our willingness to accept risks when treating the object, and is related to factors such as cultural value, historic significance and rarity. This would obviously be very low for Treasures items, but even with objects assigned a higher risk appetite, we would not act recklessly or without planning – we may, however, be willing to consider more interventive or extensive treatments to enable the item to be more widely accessed.

Figure 4: A flowchart indicating the decision-making process for the treatment of iron gall ink on paper.

[Figure 4] Decision-making for the treatment of IGI on paper.

This scheme is not prescriptive, however, and each object would be assessed and treated on its own merits. Furthermore, sometimes the best conservation decision is to carry out no treatment at all, and in all cases our work is underpinned by good preventive conservation, in the form of appropriate storage, suitable environmental conditions and sympathetic handling.

Figure 5: A British Library conservator carrying out immersion treatment of a paper manuscript with iron gall ink.

[Figure 5] Aqueous treatment of poor condition IGI on paper, in the BL’s conservation studio.

Many thanks to the Thriplow Charitable Trust for supporting this research.

22 October 2020

On light: conserving material for our exhibition Unfinished Business: The Fight for Women’s Rights

Alexa McNaught-Reynolds, Conservation Exhibition and Loan Manager

Two of the items selected for display in our exhibition: Unfinished Business: The Fight for Women’s Rights appear to be in good condition but have vulnerabilities that may not be immediately obvious. In Conservation we strive to understand every component of an object in order to recommend the best course of action for their long-term care.

Item 1. NEWS.REG170: Daily Mirror front cover: Tuesday 28th March 2017

Vulnerability: newspaper is not made to last

This is an important item in the exhibition, highlighting how strong working women are still sometimes represented in the media today. Newspapers are produced from poor quality wood pulp that is inherently unstable due to something called lignin, and they are not made to last. Lignin makes the paper acidic and when placed in direct sunlight, as many of you will have seen, newspapers turn yellow and become brittle very quickly.

Controversial front page of the Daily Mirror on Tuesday 28th March 2017 showing Theresa May and Nicola Sturgeon. The headline reads 'Never mind Brexit, who won Legs-it!'

Figure 1: Controversial front page of the Daily Mirror on Tuesday 28th March 2017 (NEWS.REG170)

We strive to protect our newspaper collection by storing them in alkaline buffered material, in a stable environment free from exposure to light sources. These actions significantly slow the degradation process.

But what about when one is requested for exhibition? While we are familiar with the vulnerabilities of newspaper generally, we are not sure how stable the media will be under exhibition conditions. The exhibition environment is very stable and the newspaper is subjected to low levels of light. While light level is low, with no UV, and the time is restricted, we are not sure how much of an effect this limited light exposure will have on the media.

In order to get a better understanding of how the media will fair under exhibition conditions, we will be monitoring this item closely. To do this, we are measuring the colour by using simple colorimetry. This is completed with 'Lab*' colour measurements which is a method of representing colour using numerical values, in a similar way to the more familiar RGB or CMYK systems. One of the particular advantages of the Lab* system is that it is based on the way in which the human eye and brain observe colours and determine differences between colours. 'L' represents lightness, from 0 (pure black) to 100 (pure white), while 'a' measures the green-red axis (negative values are green and positive values, red) and 'b' measures the blue-yellow axis (negative values are blue and positive values, yellow). The system is capable of detecting colour changes smaller than the human eye can observe, and so gives us another tool to help us provide the best possible stewardship for the items in our collection.

Controversial front page of the Daily Mirror on Tuesday 28th March 2017 showing Theresa May and Nicola Sturgeon. The headline reads 'Never mind Brexit, who won Legs-it!' This image has been labelled with yellow lines and numbers showing where colour measurements were taken.

Figure 2: Front page of the Daily Mirror with areas marked in yellow indicating where colour measurements were taken.

Highlighted in the image above are the areas where the colours were measured. The same areas will be re-measured at the end of the exhibition. This will detect any colour changes that have happened (hopefully none) and will inform the future display limitations of this item and for other similar contemporary newspapers.

Item 2. Add MS 88899/6/13:  Greenham fence wire from the Angela Carter archive

Vulnerability: highlighter ink loses colour under light exposure

This item is a piece of wire cut from the perimeter fence of RAF Greenham Common Airbase during anti-nuclear protests by the Women's Peace Camp and sent to the novelist Angela Carter who was against nuclear weapons. It was attached to a record card through two punched holes in the centre with typed notes above and below the wire.

Greenham fence wire piercing a white flash card from the Angela Carter archive with high-lighted typed message.

Figure 3: Add MS 88899/6/13:  Greenham fence wire from the Angela Carter archive with highlighted typed message.

Although the item itself is in good condition, highlighter pen was used over the top of the typed message. Highlighter pens contain fluorescent colours which are notoriously light sensitive; they will not retain their colour over extended periods of light exposure. For this reason, we will be displaying this item at our exhibition under low light levels but we will also be limiting future display in order to preserve the bright colour.

At the British Library we aim to make everything as accessible as possible so that everyone can enjoy the collection and see the items in their original condition. However, in order to preserve the collection some items do need to be restricted for various reasons, such as fragile condition, or in these cases, to limit their light exposure and preserve the bright colours for future researchers to see.  Although this means that some items can only be able to be exhibited for short periods, there are alternative solutions for display. For items that were mass produced or have multiple copies, it is possible that a replacement can be found. When an item is unique or other copies are not available, we can suggest a high-quality facsimile be made, this way the viewer can see the uninterrupted exhibition story. In this way, we can maintain the integrity of our collection for as long as possible, as well as finding ways for everyone to enjoy it in the meantime.

Fortunately, both original items will be displayed in ‘Unfinished Business: The Fight for women’s Rights’.

19 February 2018

Digitising books as objects: The invisible made visible

Book conservator Flavio Marzo explores how the experience for users of online library material surrogates could be easily improved by enhancing invisible physical features of books.

Working as a book conservator within digitisation projects has been my job for many years. I started in 2006, only one year after joining the British Library Conservation team here in London after leaving my country, Italy.

The subject of that digitisation project was the digitisation and virtual reunification of the Codex Sinaiticus, possibly one of the most known and valuable manuscripts in the Western world. The Codex was compiled in the IV century AD and is the oldest surviving and most complete version of the Old and New Testament. Many years have passed since that project and digitisation has become a common work stream within public institutions. This is especially evident within libraries which now compete in uploading material from their own collections to make them available for scholars, students and readers across the globe.

Technology has improved immensely since then and a lot of ‘ink’ has been spread across physical and virtual pages about the remit, the limitations and the advantages of what is offered to the public through the surrogates uploaded onto countless web portals. This piece is just another little drop into this ocean of ink to share some considerations built upon experience and from the perspective of a book conservator who sees, because of his professional background, the limitations of this, but also the exciting challenges to overcome them.

Books are physical objects and the pleasure of opening them, turning the pages, looking at (when decorated) the illuminations and their pigments, or at the accretions of the ink strokes, even smelling them, cannot be recreated on the screen of a home desktop. This does not mean that we cannot improve the experience and possibly further close the gap between the real object and the two-dimensional images.

I now work for the British Library/Qatar Foundation Digitisation Project and for the past 5 years, with a team of two conservators, I have been repairing documents (printed and hand written) and Scientific Arabic manuscripts for the team of scholars and photographers who are doing the real magic by gifting the world with the content now available on the Qatar Digital Library website (https://www.qdl.qa/en).

I have worked with books all my life since I was a 16 year old apprentice in a Benedictine Monastery. I have to admit that I am not an avid reader but I love books as objects and I get very excited about all the different little features and materials they are made from. How is it possible to please someone like me when offering online surrogates of complex items like books?

Books are recognised as 3D items and a lot of work has been done to migrate the content of those printed and manuscript texts into online, easy to access versions, but very little has been done to capture their physicality as objects.

Photographers, like any other professional, follow strict professional standards defined by general rules and specific project boundaries. Those standards are built to assure that the best possible result is achieved consistently and the meter to measure this result is the quality of the final product i.e. the image to be uploaded. Those images are supposed to reproduce as faithfully as possible the text and the carrier of the content of a book. Very rarely attention is given to the substrate or to the physical features of the object.

Lights for digitisation are carefully positioned to avoid shadows and they help to reduce surface irregularities and anomalies. This is all to the benefit of the written text and/or of the decorations, but with much loss for the lovers of the book as an object!

Here I want to describe some very practical ways to achieve different results and show some ‘behind the scenes’ of items I have been working on and how these very interesting results can be achieved with simple straight-forward techniques that do not require any high-tech equipment.

Raking light

I have mentioned the Codex Sinaiticus and I would like to start with it.

An image from the Codex Sinaiticus showing the page as viewed under normal light conditions.
Revelation, 2:7 - 3:5, British Library folio: 326. This image: Normal light.
The same image from the Codex Sinaiticus showing the page as viewed under raking light conditions, which shows as a much darker image..
Revelation, 2:7 - 3:5, British Library folio: 326. This image: Raking light.

 

All the available remaining pages of the Codex from the different geographical sites where they are presently held (The British library, The Library of the University of Leipzig, The National Library of Russia in Saint Petersburg, and the Holy Monastery of Saint Catherine’s) were digitised and uploaded onto the purposely created website (http://www.codexsinaiticus.org/en/). Contrary to common practice, all the pages were imaged both with normal and ‘raking light’. 

When imaging pages of books with normal light the attention is placed primarily to achieve the full readability of the text. Lights are placed and conditioned to radiate evenly over the surface of the page making sure no shadows are created and paying great attention to colours and tones to ensure they are as close as possible to the real appearance of the object reproduced.

What ‘raking light’ does is very different and the resulting image reveals a completely new landscape. Placing the source of light horizontally relative to the page results in an enhanced texture of the substrate which highlights and brings to life all the physical features present on the surface of the pages. These interesting and unique features can relate to the preparation of the writing surface or more generally to the specific material the substrate is made of e.g. papyrus, parchment or paper.

Here are some details of pages of the Codex Sinaiticus taken with raking light.

A page of the Codex Sinaiticus cast with raking light. This light has revealed the ruling lines, both horizontally and vertically, used to keep the text in place. An image of the Codex Sinaiticus as viewed from the top of the page looking down, under raking light conditions. The light has revealed the scraping of the surface of the parchment. The image also shows pricking holes, circled in red, which was done as an aide for ruling the page as an aide for the scribes.
In the previous images the source of light is now helping us to appreciate this famous manuscript on a completely different level.

Horizontal and vertical lines, holes pierced through the page, and scratch marks now appear clearly. They are traced on the surface of the pages for a purpose; those are features related to the page preparation that happened before the text was traced onto it.

The ‘bounding lines’ (vertical) and the ‘writing lines’ (horizontal) are impressed with a blind (not too sharp) tool onto the parchment sheets. The holes, highlighted with red circles in the second image, are used as a reference. This is known as pricking holes for the ruling of the page to provide the scribes with a guide for writing.

The scratches visible on the surface of the page are most likely the marks left by the pumice stone. The pumice stone was commonly used to prepare the surface of the abraded parchment sheet to make it more absorbent and therefore improve the grasp between the grease substrate and the writing ink.

Thanks to this lighting system it is also possible to see the direction of the indentation of those lines and holes. This information can help codicologists, even from the comfort of their homes, to understand from which side of the folio they were traced and pierced and so recreate the step by step process of the creation of an ancient manuscript.       

One of two images of a letter sent by the Emir of Baghdad to Lord Curzon in 1899. This image is taken under normal light conditions, with clear neat Arabic script contained in two borders, underneath a decorative image heading in red and gold.  The same letter from Emir to Lord Curzon as taken under raking light conditions. This image has revealed how the image was folded, and the number of folds that can now be seen, that were not visible under normal light conditions.
In this image we see the images of a letter sent by the Emir of Bagdad in 1899 to Lord Curzon when he was appointed Viceroy of India, first taken with normal and then with ‘raking light’. In the first image the letter is just a sheet of paper beautifully arranged and decorated with writing. In the second image the light tells us a completely different story; it shows us the use of this letter, the way it was folded and the number of folds it had.

How incredible that it is possible to see all these different insights by just slightly moving a lamp!

Transmitted light

Another technique to read paper from a different perspective is using ‘transmitted light’. 

This image of the same letter from the Emir of Baghdad to the Lord Curzon, is now revealed under transmitted light, another technique of reading paper, to have a watermark, with a Lion holding a flag bearing the word 'Reliance' within a circular sigil entitled around the inner edge as 'The Lion Brand, Croxley number 693, London. some watermark text is obscured by the overwriting Arabic script.

Simply by placing the same sheet of paper onto a light table (i.e. illuminating from below) it is possible to bring a completely new scenario to life. In this image for example we can clearly see the watermark impressed onto the sheet of paper of the previous letter, detail impossible to be seen only looking at the image taken under normal light.

Paper can be hand or machine made, and sheets can bear chain and wire lines or possess watermarks or not. These details can be of great interest to scholars and add valuable information to the understanding of documents in relation to their use and circulation.     

A page manufactured using laid and wove paper, which is revealed distinctively by transmitted light, showing the chain and wire lines on the paper. On the page itself can be seen a large central watermark of a Sphinx like creature with a crown between it's wings. On the left hand side of the page is arabic script in red, with text in black handwriting on the right hand side of the page.   a comparison to the left hand image of  laid and wove paper, this image of a machine-wove page from the India Office Records, shows the difference in paper, with no chain and wire lines and a clearer paper. The Page itself has again, a large watermark underneath the text, of the words 'Government of India'. Superimposed is flowing cursive handwriting in black ink.

Here are some more examples of sheets of laid and wove paper taken from different files from the India Office Record material, some showing again the characteristic chain and wire lines (except the last one which is actually a sheet of machine made wove paper) and some very distinctive water marks highlighted and made visible thanks to the used of transmitted light. 

Visualization of the physical collation of manuscripts

Books are made of folios and pages and those folios are ‘bound’ together. How the bindings are made is one of the real wonders of books. The variances are numberless and the materials and details of execution not only delight nerds like myself, but more importantly they inform researchers about the history of those books, giving insights into the objects that open doors to sometime unexpected cultural landscapes through links between different craftsmanship and cultures.

To describe a book structure is a very delicate and laborious process, but one that conservators are trained to do and that they automatically do many times when conserving those books as they record the treatments being carried out.

A lot of work has been done during recent years to create tools able to easily make this complex information sharable with the wider audiences. One I wish to mention here is VisColl, developed by Dot Porter at the Schoenberg Institute for Manuscript Studies at the University of Pennsylvania (https://github.com/leoba/VisColl) in collaboration with Alberto Campagnolo at the Library of Congress, a friend and colleague.

A image capture of a page from the University of Pensylvania, of a program called VisColl. The image, with a muted blue background, shows four images of a digitised manuscript, with a section on the left hand side showing the structure of the book and the pages digitised, in white.

In this image we have, additional to the images of the digitised pages, diagrams (on the left) of the structure of the section where those pages are located and, highlighted in white, the specific pages shown on the screen.

Those diagrams, surely more easily understandable than many wordy descriptions, can help researchers to step into a completely new level of understanding for the manuscript, providing vital information about the history of those items, the way they were put together and possibly evidences of late alterations or even forgeries which may have occurred throughout the centuries.

Digitisation has opened new ways to look and make use of books and, I believe, the improvement of understanding of physical features is the next step that should be consistently and widely taken to enhance the online user experience.

One of the issues digitisation has brought to the attention of conservators and professionals involved in the care and preservation of library material is the fact that by enhancing the ‘fame’ of objects we can cause an increase in how much those same objects are requested for access.

To justify restriction in handling objects, which for the most part are very fragile and extremely valuable, we need to improve the online metadata and the amount of information available with the surrogates. Those presented here are just some examples in how, quite easily, this can be done.

Obviously the smell will stay within the walls of the libraries, but those are pleasures to be experienced in situ, and alone (almost..!) at the table of the reading rooms. No surrogate can replace that for the lovers of books. 

24 July 2017

Do more together than we can ourselves: The unique partnership between curator and conservator

Zoë Miller and Peter Toth

curator, n. Traditionally, a curator or keeper of a cultural heritage institution (e.g. gallery, museum, library, or archive) is a content specialist charged with an institution's collections and involved with the interpretation of heritage material.

conservator, n. A person employed in the conservation of artefacts or sites of archaeological, historical, or cultural significance. Cf. conservation n. 1f.

The British Library is the custodian of thousands of manuscript treasures and it is a shared duty of its curators and conservators to care for and interpret them. I’m inviting you to share this meeting of minds and how it brings our collection to life through the rediscovery of a unique fourteenth century manuscript; Egerton MS 2516.

Once part of the library of bibliophile friar Leonardo Mansueti of Perugia (d.1480), this fragile selection of writings from Cicero and the famous African magician and philosopher Apuleius was brought to our conservation studio by curator Peter Toth for assessment and treatment advice.  

A portion of Parchment showing writing done in two lines in red gothic script. Underneath the red writing is a thinner black handwriting, and underneath that is two separate decorative twined borders, one in red and the other in black. The parchment itself is patchy in color, and the black dots are the hair follicles from the animal skin.
Ownership note by Leonardo Mansueti in Egerton MS 2516, f. 162r.

 

The volume had been rebound in the nineteenth century in a style and design typical of the collection of Francis Henry Egerton. The very small script was written in iron gall ink on thin parchment to save money, and decoration was kept to a minimum. This book was destined to be a scholarly study text and it is an early and important manuscript of the works of the second-century Apuleius.

A hand opening the cover of the manuscript, bound in brown leather, with a thin gold border. The manuscript is resting on a green cutting board.

The maunscript resting opened, showing the tight nature of its binding preventing the pages from lying flat on one side. A white snake weight is utilised on the right hand side of the manuscript, to keep the pages from folding back and closing. The book itself is resting on dark gray plastazote book supports, on a light grey table.
The tight opening of Egerton MS 2516.

 

Peter is able to read and interpret the ancient text and marginalia and to provide this crucial contextual and historical narrative. When he presented us with this book we could immediately see the problem. Its materials had aged so much that it couldn’t be opened beyond forty five degrees! It was so tight that we could not see the text in the gutter. The pages were fragmented, mutilated and corroded by the chemical action typical of this ink. Like leaf skeletons they were incredibly fragile and impossible to turn.

A section of the parchment leaves of the manuscript, showing the two blocks of gothic style text in black ink, running down the page in two neat parallel columns. The damage to the parchment can be seen in the staining of the parchment, including over the text, while there are tears and missing sections around the lower end of the pages.
Damaged folios and cut marks in Egerton MS 2516.
Two large cut marks in the manuscript pages, on opposing sides of the parchment leaves as the book is opened.
Cut marks in Egerton MS 2516.

 

As conservators, our first sight and handling of an object can play like a movie of its life. We experience the ageing character and material signs of use and damage known so well of leather, parchment, threads and paper. Even the smells and stains, the cuts, marks and tears of a hundred scholars thumbing the pages are brought to life as we hold it in our hands. There were mysterious cuts to the tail of many folios, which suggested a purposeful extraction. Could this have been to remove mould, mistakes or secret text? Perhaps the parchment was stolen for love notes by a fifteenth century student? 

The existing book boards with a gold crest and inscriptions are part of the unique provenance of this object, and yet the re-binding destroyed evidence of the manuscript’s original shape and sewing. Peter explained that its hard work as an academic ‘set text’ contributed to the patterns of deterioration we see today. We therefore tailored our treatments to preserve evidence of this damage and limit our repairs and intervention to safeguard the narrative. We created a new binding from calfskin replicating the Egerton tradition to respect this significant part of its history.

A hand with a metal conservation flat spatula tool, is gently removing the sewing from the manuscript, showing as a white thread. The manuscript is lying open on its supports. The damage to the parchment can be seen in the many tears and creasesm as well as ink stains obscuring some text.
Removing sewing from Egerton MS 2516.

 

The old leather, glues and overcast sewing threads were painstakingly removed by parchment specialist intern Camille Thuet. Once the delicate folios had been released, medieval manuscript cataloguer Laure Miolo was able to access and identify hidden marginal notes. She found fifteenth and sixteenth century comments and a Greek quotation from Euripides which had been added by early readers of the text and reveal how it was used and interpreted. 

Formerly hidden areas of parchment have now been exposed during treatment. This section shows a portion of the latin text, in black, with a bold red capital. Underneath the text box is a partial handwritten notation in Greek, in now faded black ink.
Quotation from Euripides in the lower margin of Egerton MS 2516, f. 123v.

 

With the help of conservation imaging scientist Christina Duffy, Camille analysed dark stains across areas of script which were speculated to be early attempts at revealing hidden text. Multi-spectral imaging was also useful in enhancing faded marginalia.

Chemical damage to the manuscript on its lower left page. The damage appears as a shiny brown stain coating the lower lines of text. Underneath can be seen the acidity of the Iron Gall ink having eaten through the parchment in places.
Historical chemical damage on Egerton MS 2516 f. 4r in an attempt to improve legibility of corroded iron gall ink.

 

Three images of the same page of parchment, undergoing Multi-spectral analysis. The first image appears normal, while the middle image has a multi-hued purple sheen, while the right hand image is in more greyscale.
Multi-spectral imaging of Egerton MS 2516, f. 116r.

 

The treatment proposal had two clear aims: 

Enabling access and digitisation through repair of the delicate and damaged folios to ensure they continue to exist for future generations

Preserving and protecting historical evidence so that as much of the past is accessible to the future reader.

A new guard book structure means that the original parchment text block is protected from adhesive and the necessary mechanics of the binding’s spine. This allows every part of it to be viewed, and no part to be constricted. Parchment likes to breathe!

A new guard structure inserted into the spine of the book, with a green backing onto the spine's leather cover. This has enabled the parchment to lie flatter on either side of the opened book.
New guard structure.

 

After treatment, the manuscript in this image is shown to lie much more flatter, and the pages much more easily opened. The new guard structure can be seen running up the spine and gutters of the parchment pages, helping the parchment lie flat.
New flat opening.

 

The new binding of the manuscript in a tan leather. As yet there is no text on the binding, though the spine shows five double lined decorative cords.
New binding.

 

The manuscript with its new gold leaf text and decoration added. The Book is lying nestled in a wooden vice, while the author of the book, Cicero, can be seen atop the title. The cords have been embellished in gold leaf as well. Next to the manuscript and vice is a cushion containing the remnants of the gold leaf, with the handle of the gold knife used to collect the gold leaf is just visible on the right.
Gold finishing on Egerton MS 2516.

 

The books in our rich collection inspire both for the intellectual information they carry and as artefacts of craft. We were able to make complex conservation decisions to preserve this manuscript through collaboration with curators. We must together protect what our collection will represent in the future where respect for such treasured objects only grows in this changing digital age.

Thanks to Camille Thuet for her observant eye and parchment knowledge, and to Peter Toth, Andrea Clarke, and Laure Miolo for their historical expertise. The manuscript has now been restored and completely digitised and is available at the Library’s Digitised Manuscripts site here.

24 November 2016

Applications of Image Processing Software to Archival Material

Images of archival material are useful to both conservators for monitoring changes, and to researchers for detailed analysis and permanent access to collection items. Image processing allows historical documents and other collection items to be studied without the risk of damage to the primary source. The increase in digitisation projects is generating large volumes of image files that can be processed to enhance the understanding of our collections without physically handling fragile material.

ImageJ is a powerful public domain Java-based image processing package. The nature of open source software allows for the constant update and availability of new plugins and recordable macros designed for specific tasks. ImageJ’s built-in editor and a Java compiler allow for the development of custom acquisition, analysis and processing plugins. In April 2013 I presented a poster at the ICOM Graphics Documents Working Group Interim Meeting in Vienna, outlining the applications of image processing software to archival material . The full poster can be downloaded as a PDF here.

The poster made by Dr. Christina Duffy which showcases the work that can be done with image processing software such as digital image enhancement and watermark extraction.

While several improvements have been made to the functionality of ImageJ since 2013, I hope this poster provides useful information to those less familiar with image processing techniques.

ImageJ was originally designed for the purpose of medical imaging by the National Institutes for Health by Wayne Rasband, but has since found applications in many fields. It can be run on any computer with a Java 5 or later virtual machine, as an online applet or as a downloadable application (Microsoft Windows, Mac OS, Mac OSX, Linux, Sharp Zaurus PDA). ImageJ offers features similar to commercially available image processing software packages such as brightness/contrast adjustment, frequency domain filtering, binarisation and particle analysis.

Christina Duffy

22 August 2016

Hidden horoscopes and puzzling predictions in Papyrus 98

Why would certain passages from an ancient horoscope and related predictions be smudged and partially erased? This is what researchers are currently trying to determine using multi-spectral images recently captured of Papyrus 98.

Glass enclosure of Papyrus 98.

Papyrus 98 (British Library Pap. XCVIII) is fully digitised and can be viewed online here.

The British Library holds over 3000 papyri, along with several thousand unframed fragments. Western Heritage Collections cares for our Greek and Latin papyri, while papyri in other languages are found in our Asian and African Collections. The papyri collections are sequentially numbered running from Papyrus 1 – Papyrus 3136 with a separate sequence of 37 items forming the Egerton Papyri collection.

Papyrus 98 underwent multi-spectral imaging to improve legibility on some partially erased and smudged passages. Papyrus 98 is housed in a glass enclosure with inscriptions visible on both the recto and verso. The original collector was most interested in the Funeral Oration of Hyperides over Leosthenes and his comrades in the Lamian war [BC 323] which was placed in the recto position at the front of the glass frame. This partially imperfect Greek text is thought to date to 1/2 century CE with the greater portion of the oration in fourteen columns. However, it has since been discovered that it is on the verso of the current housing where the oldest and first text was inscribed on the papyrus.

The items sits on a table while being imaged.
Due to the long profile, multi-spectral imaging of Papyrus 98 was achieved by imaging the manuscript in sections and digitally stitching the images together.

On this 'verso' side is an astrological treatise consisting of three and three-quarter columns of a Greek language horoscope partially in small uncial characters similar to those of Hyperides. This is followed by an Egyptian language set of predictions relating to the horoscope written in cursive handwriting in what is referred to as 'the Old Coptic Script'. The Papyrus 98 manuscript showcases the earliest example of this Old Coptic Script.

The overall majority of the Greek text in this manuscript is in excellent condition, with the exception of the partially erased sections at the bottom of column III and IV which precede the lines in which the Egyptian language section begins. Other areas of faded or partially rubbed out sections were also identified and hoped to be recovered with multi-spectral imaging.

Close-ups of text on the object in Infra-red and ultraviolet.
Top: Infra-red image of Papyrus 98 showing uncial Greek in the left column and cursive Egyptian (Old Coptic Script) in the right column. Bottom: A composite colour ultra-violet image of Papyrus 98.

 

Researchers are still going through the results trying to figure out why these particular passages were erased and what was, or is, the significance of the obscured text. While the raw images have provided some clarity in certain areas, there are several algorithms which will be run on the data set to isolate and enhance the blurred regions. This is just one of many projects that our conservation team are working on to aid scholarly research and enable further access through digital means.

A side-by-side of two imaging processes; on the right you can see streaks of different colours.
Left: Original image showing fragmented sections of Papyrus 98. Right: Colour space analysis showing the same region in pseudo-colour.

A small number of British Library papyri have been digitised in full and can be viewed on Digitised Manuscripts. Further information about published papyri can be found on the Trismegistos database. More about this collection item can be found on the Explore Archives and Manuscripts resource, while further information about our Greek and Latin papyri collections can be found here.

Dr Christina Duffy

 

28 April 2016

Much Ado About…Possibly Something

Conservator Flavio Marzo reports on his fascinating findings during the conservation of one of the books bearing the presumed signature of William Shakespeare.

As it is now the 400th anniversary of the death of William Shakespeare and the British Library has unveiled a major exhibition about the Bard of Avon, I thought it was a good time to share the conservation work I carried out on one of the items currently on exhibition. In 2005 I was given the opportunity to work on an item here at the British Library bearing one of the few surviving (possible) signatures of the poet. The book, possibly part of Shakespeare’s personal library, is a copy of “The Essayes of Morall, Politike and Militaire Discourses” written by Michaell Montaigne and published in London in 1603. The volume was sent to the conservation studio to be treated before being sent out on a loan and presented some very interesting and unusual features.

The Examination

The cover and the book block were detached and the main task was to secure them together ensuring that any treatment was clearly visible and unobtrusive.

Left image: The front cover of the book in a medium brown leather with decorative gold tooling around the edges of the book, and a rectangle with a diamond shaped design at the centre. Right: The book cover has detached from the textblock, with the spine cover and front board resting on the table away from the textblock.
Left: Front cover. Right: Cover and book block detached.

The sewing of the body of the book, most likely the result of a quite recent restoration campaign, was made on five narrow strips of tanned brown leather. Probably at the same time new end leaves were added and secured to the first and last sections through an over-casted stitching. There was no evidence of spine lining or glue applied to the spine. When the cover was removed the original sewing supports remained laced through the boards and the page with Shakespeare’s presumed signature was attached on the inside of the left board.

The detached cover rests open on the table, with laces visible along the spine and handwritten text visible on the left board.
The inside of the detached cover with the signature page and the original supports laced with the cover.

The original sewing supports were made of strips of alum tawed leather with a second layer of tanned brown leather added to give thickness to the raised bands ensuring their visibility on the spine of the book.

Left: a close up of the white alum tawed leather support. Right: A close up of the spine showing the raised area where the leather cord rests behind the brown leather.
Left (viewing from the inside): A strip of alum tawed leather with clear distortions due to the original passages of the thread of the original sewing. Right (viewing from the outside): One of the trimmed tanned leather strips used to create the raised effect on the spine cover.

Areas of the leather cover were missing at the head and tail. After a thorough examination of the cover I realised that the page bearing the signature, adhered onto the inside of the left board, was not originally attached as a paste down, and in fact was never originally placed at the beginning of the book. Careful visual examination revealed that a raised oval was showing through the page.

An image of a page showing the oval at the bottom centre and handwritten text above it.
An image of the page taken with raking light clearly showing an oval shaped imprint from the recto of the page.

Since the page was adhered to the board along the edges only, it was possible to insert a light sheet between the page and the board. Under transmitted light it was possible to capture an image of what became clearly identifiable as a British Museum stamp - proving that this sheet was, until quite recently, still detached. Under transmitted light it was also possible to locate and record the watermark present on this page.

Left: A close up of the British Museum stamp in red. Right: A close up of the watermark.
Left: British Museum stamp imaged with transmitted light. Right: Watermark of the page with the signature.

This watermark was subsequently compared with others found on the pages within the book block. Although no perfect match was found between the watermarks, there was a very strong similarity between them.

A set of three similar watermarks; they appear to resemble a vase with handles and an ornate topper.
Other watermarks found within the book block.

Another detail that immediately caught my attention was the observation that the damages along the edges of this sheet did not match the losses and tears present along the edges of the first page of the book.

Two sheets of paper side by side to show the inconsistency in staining and damage.
Mapping of the stains and damages show how different and inconsistent they are along the edges of the two sheets.

Remarkably, these damaged areas matched almost perfectly to the last restored original end leaf of the book-block proving that this sheet was originally placed at the back of the book and not at the beginning.

Two sheets side by side which have similar damaged areas.
Matching damaged areas between the signature sheet and the last right end leaf.

The Repairs

The conservation of the volume involved the removal of the leather strip supports. These supports were failing and becoming brittle due to the acidic nature of the tanned leather. The strips were mechanically removed from the sewing thread passages and replaced with new linen tapes so that the book did not have to be re-sewn.

Left: The leather strip is removed with an awl. Right: The new strip has been added.
Removal of the leather strips (left) and their replacement with new linen tapes (right).

The leather of the cover was reinforced and in-filled with dyed Japanese paper and wheat starch paste.

Left: Strips of white Japanese tissue are added to the spine for reinforcement. Right: Toned Japanese tissue to match the brown leather has been added to the leather cover for support.
Japanese paper and wheat starch paste are used because of their strength and reversibility.

A new spine lining made of light cotton fabric was adhered to the spine of the book-block to further secure the sewing. The extensions of this spine lining with the frayed linen supports were then inserted between the leather and the boards and adhered to the boards to secure the book-block back with its cover.

The book lays open to its front page with the cotton strips in the process of being tucked under the front board.
The strips of cotton fabric are adhered between the leather cover and the boards to secure the book-block with the cover.

Conclusions

It is hard to say why this page was tampered with. Possibly it was thought that by attaching this page to the front board it would become more difficult to steal. Sometimes conservation needs some forensic skills, but it always requires great attention to detail. Physical features when correctly interpreted can tell us a lot about the history of an item. It is extremely important when repairing items of historical value that conservators are careful not to inadvertently hide or remove features which may later prove to be significant.

This work, carried out a long time ago, is today still one of my most cherished projects. I am very pleased to be able to share it with you, especially during this year so significant in the history of the Great William Shakespeare.

Flavio Marzo

See this intriguing collection item for yourself at our exhibition: Shakespeare in Ten Acts open until Tuesday 6 September.

18 January 2016

Hidden figure in Leonardo da Vinci notebook revealed

Multi-spectral imaging at the British Library has revealed a figure, in previously unseen detail, on a folio of a notebook belonging to Leonardo da Vinci. Da Vinci expert Professor Martin Kemp believes the sketch may be part of a series of 'fugitive images' occasionally unearthed on da Vinci's work.

Two images of the same area of the Da Vinci page, one showing a erased area, the next showing a standing figure now visible under multi-spectral imaging.
A comparison of the erasure as seen by the naked eye (left) and the revealed figure (right) after multi-spectral imaging.

 

Leonardo da Vinci (1452 – 1519) was a prolific note-taker with over 7,000 pages of his thoughts surviving today. The British Library is custodian of a notebook known as Codex Arundel 263 after its English collector Thomas Howard, 14th Earl of Arundel. These notes and sketches come from different periods in da Vinci's life, though most date to 1508, and cover a range of topics including mechanics, astronomy, optics, architecture and the flight of birds.

Codex Arundel 263 was not originally a bound volume, but was put together after his death. The variation in folio type and size show how many of da Vinci's ideas, studies and inventions were observed outdoors as he went about his day. The notes are written in Italian showcasing his famous left-handed mirror writing. Folios 137v and 136r, housed together and currently on display in the British Library Treasures Gallery, were taken for multi-spectral imaging analysis to enhance and potentially reveal a hidden sketch in a small area of discolouration visible in the lower half of folio 137v.

Dr Christina Duffy standing to the right of an exhibition case showing two pages of the Da Vinci Arundel notebook. The pages are framed in mountboard with placards in front of them.
Imaging Scientist Dr Christina Duffy with Codex Arundel 263.

 

The smudge measures no more than 6 x 3 cm and has been suspected by scholars to contain an elusive sketch of a figure by da Vinci - possibly erased by himself.

Folio 136r and 137v shown as two ajoined pages opened out. The paper, of a brownish tint, contains designs and writings both vertically & horizontally, with the left-hand folio showing the darkened smudge containing the hidden figure at the lower right.
Codex Arundel 263 folio 136r and 137v showing notes, calculations and diagrams including a mechanical organ and timpani/drums.

 

The analysis took place at the British Library Centre for Conservation where high resolution images of the folios and region of interest were captured. Multi-spectral imaging is one of the many tools our Conservation Science team use to non-invasively and non-destructively increase the body of knowledge on collection items for scholars, curators and conservators. The da Vinci sketch was placed underneath the monochrome sensor camera and exposed to light of various wavelengths ranging from the ultraviolet at 365 nm to the near infrared at 1050 nm.

Multispectral Imaging machine. The room is filled with ultraviolet light, with a brighter light on the table where the image will be exposed, underneath the multi-spectral camera. Two reflective boards are tilted at an angle either side of the camera, while behind them are two lights on tall stands.
The Multi-spectral Imaging system is based in the British Library Centre for Conservation. 

 

These wavelengths reside on what is known as the Electromagnetic Spectrum - a wide spectrum encompassing radio and X-rays. The human eye can only detect light within the visible region of this spectrum limiting our ability to see potentially faded or invisible information. Multi-spectral imaging therefore enables the capture of detail which we cannot see with the naked eye.

The British Library imaging system acquired multiple images of the folio at several different wavelengths from the ultraviolet to the near-infrared.

Filters placed underneath the camera's lens were also used in combination with the lights to capture images of fluorescence resulting in the generation of vivid images highlighting the fugitive figure on folio 137v. The images raise fascinating questions about why the figure was drawn here, and why great efforts were made to erase it.

A Pseudocolor image of the Da Vinci pages, created using three different filters in Multi-spectral imaging. The page shows as mostly light blue, with yellow around the edge, centre and towards the top right in patches. The text and images show as black, while in the erased area, the figure can now be seen, also in black but less pronounced.
This pseudocolour image was generated by combining three monochrome multi-spectral images captured using ultraviolet light with a red, green and blue filter respectively.

 

Multi-spectral imaging is an incredibly exciting process and has revealed many secrets from our collections to date, including recovering once thought lost text from the 'Burnt Magna Carta' last year. It is an incredible privilege to work with some of the world's most valued treasures and subject experts. Everyday brings new discoveries to light (quite literally!) and the prospect of unlocking more secrets from the British Library's vast and varied collections is thrilling.

The entire Codex Arundel notebook has been digitised and is available to view online

Dr Christina Duffy (@DuffyChristina)

 

23 October 2015

Magna Carta Conservation Team at the ICON Awards

The British Library conservation team that worked on the Magna Carta project attended a glamorous awards ceremony at the Institution of Mechanical Engineers last night. The team were shortlisted for the Institute of Conservation (ICONAnna Plowden Trust Award for Research and Innovation, which went to Tate for their impressive Rothko Conservation Project. A huge congratulations to the Tate team and to the Imperial War Museum who were also in our category for their amazing space vacuums, air bazookas and duster drones project in the War Against Dust.

Four members of the Magna Carta conservation team stand to have their picture taken; they are standing in front of a dark wood wall.
Left to right: Cordelia Rogerson, Christina Duffy, Gavin Moorhead, Julian Harrison

The Magna Carta Project was a collaborative process of sophisticated research and innovation that enabled a pragmatic solution for rehousing and displaying an iconic document. Our biggest challenge was overcoming long held preconceptions and expectations that a high profile artefact required an expensive high-tech approach. You can read more about our work here.

Flyers for the Icon Conservation Awards rest on a table. They list information about the event such as date, time, and location.

It has been a great privilege to work with Magna Carta and the curatorial team in the build up to the British Library's most successful exhibition Magna Carta: Law, Liberty, Legacy.

Many thanks to all colleagues across the British Library and other institutions who helped progress the project into something we are all very proud of. Thanks to ICON and their sponsors Beko for organising a terrific night celebrating an incredible range of conservation work going on around the UK.

Congratulations to all the entrants, shortlistees and winners!

Christina Duffy

06 July 2015

Under the Microscope with Magna Carta

We recently held a very successful public event sharing our conservation work in preparation for the British Library Magna Carta: Law, Liberty, Legacy exhibition. The exhibition marks 800 glorious years of Magna Carta since it was granted by King John of England in 1215. The conservation project involved removing six manuscripts from their frames and rehousing them for display. While they were out of their frames, the manuscripts were examined using various scientific techniques. High-resolution digital microscopy enabled incredible magnification of the iron gall ink and parchment which make up the charters. Here is a selection of the images captured of Cotton MS Augustus ii.106, one of the British Library’s two original Magna Cartas dating to 15 June 1215. Enjoy!

The Magna Carta rests on a platform with a microscope above it which Christina Duffy looks through.
Imaging Scientist Christina Duffy
A full view of Magna Carta 1215. It is a rectangular pieces of parchment with small text.
Magna Carta 1215

Magna Carta 1215 (Cotton MS Augustus ii.106) – one of four surviving original 1215 copies.

Iron gall ink

Iron gall ink has been used since the middle-ages and is found on many of our most treasured collections including the Lindisfarne Gospels, Beowulf and Magna Carta. The main ingredients of iron gall ink include iron sulphate, tannins from oak galls and water. Overall the ink is in very good condition on this charter allowing us to appreciate the beauty in the detail of some of the intials.

A close up of the bottom left of Magna Carta 1215.
Magna Carta 1215 detail

 

20X magnification showing an uppercase letter which looks like an O that has been half filled in, with dotted lines going down the centre.
Iron gall ink at 20x
An even closer image of the O - some cracks are visible.
Iron gall ink at 30x
An even closer shot, showing loss of ink on the parchment surface.
Iron gall ink at 150x

At high magnification we can see that some areas have experienced ink loss, but the Great Charter is still legible due to the remaining ink shadow left behind. Find out more about iron gall ink in a previous post here.

A closeup of the text along the right hand side of the Magna Carta. Text runs in horizontal lines across the image.
Magnca Carta 1215 detail right

 

A close up of some of the text, showing a variety of letters, including ones which look like an uppercase T and O. Some loss of ink is visible.
Ink loss at 30x
An even closer look at the O shape, with cracking and link loss very visible.
Ink loss at 100x
Yet a closer look at the ink loss. At this level of magnification, the ink which is left looks like rocks or ground coffee beans.
Ink loss at 200x

Parchment

The parchment on which Magna Carta has been written is thought to be sheepskin. Parchment is an animal pelt which has had the hairs removed by liming or enzymatic action. It is then stretched and dried under tension creating a perfect writing surface with a thin opaque membrane. Below are some images showing damage to the  upper dermal layers of the parchment. Find out more about parchment here.

A close up of text in the centre of the Magna Carta.
Magna Carta 1215 detail centre

 

An even closer look at the text. There is a what looks like a hole--damage to the skin--in a oval-like shape. The right side of the oval is curved as normal but the left side is shaped like the edge of a triangle.
Damage at 30x
An even closer view of this oval-shaped damage. There is a ring of black around this hole.
Damage at 50x
An even closer look of this damage, showing that the skin is quite textured.
Damage at 150x

CC by You can find out more about this charter on the British Library Magna Carta resource page.

Christina Duffy (@DuffyChristina)

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