Warriors, Weapons and Horses: conserving folios from a Mamluk manuscript

The Mamluks ruled Syria and Egypt from 1250 until they were defeated by the Ottoman’s in 1517. Very few illustrated manuscripts from this era have survived, but one of them is held at the Chester Beatty. This bound manuscript (CBL Ar 5655), dating from the mid-14th century, is a Compendium of Military Arts featuring warfare, weaponry and horsemanship.  Twelve separate folios from the manuscript have recently been conserved in preparation for our upcoming temporary exhibition, Gift of a Lifetime (opening on 19th October 2018).

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CBL Ar 5655.134 before treatment.

The thickly applied white pigment (probably lead white) on the faces and turbans of the warriors had suffered serious cracking and in some cases small losses. In other more localised areas there was cracking and slight flaking/powdering of some pigments, particularly in association with creases in the paper. It is also likely that the smooth surface of the highly burnished paper support had contributed to the loss of media.

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Left: Cracking of media associated with creases in the paper (CBL Ar 5655.134); Right: Flaking white pigment (CBL Ar 5655.134).

All of the pigments were checked under magnification and consolidated as needed using Bermocoll, a synthetic cellulose-based adhesive. Isopropanol was applied to the edge of the flaking areas using a very fine brush, directly followed by the adhesive applied with a second brush. The alcohol acts as a wetting agent, reducing the surface tension of the adhesive so it is drawn underneath the flaking pigment layer by capillary action. On drying, the adhesive secures the fragile pigment layer to the paper below.

On a number of folios the paper along the spine edge was fragile and torn with paper fibres at risk of being lost. A small number of tears along the creases in the paper were also apparent. The folios had been repaired in the past and although these historic repairs were indiscreet it was decided that they should be left intact because they had not caused any damage to the folios and can now be considered to be part of the object’s history.

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CBL Ar 5655.159 in transmitted light, showing the historic repairs.

Repairs were carried out to stabilise the damaged areas of paper and ensure that no further damage would occur through handling. As the thin Islamic paper was particularly susceptible to distortion with the addition of moisture, the repair methods were chosen carefully to ensure that only a very small amount of moisture was introduced. The tears were repaired using remoistenable tissue, a very thin Japanese tengujo paper pre-prepared with 1% methyl cellulose adhesive. Along the spine edge the loose fibres were secured with thick wheat starch paste. In some areas bridge repairs were added to support small parts of the paper that were at risk of detaching.

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Left: Repairing a tear on CBL Ar 5655.161 using remoistenable tissue; Right: Applying small bridge repairs to the spine edge of CBL Ar 5655.162.

For the bridge repairs, Japanese paper fibres were teased out from the torn edge of a long-fibred kozo paper and rolled together between finger and thumb to create tiny bridges. The repair fibres were then pasted with wheat starch paste and positioned carefully across the damaged areas.

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Detail of the spine edge of CBL Ar 5655.134, before treatment in transmitted light (left) and after treatment (right).

Whilst working on these charming miniatures I had the chance to observe some of the techniques used by the artist(s). Scoring lines (visible in raking light) had been used to plan out the symmetrical designs and under-drawing was visible where the pigments had been lost from the faces and turbans. Interestingly, the pigment on the back of the black horses had a shiny finish and there was slight cupping of the painted surface. This suggests that a surface coating was applied locally over the black pigment before burnishing to create this lustrous finish. The undersides of the black horses were left without this additional surface treatment leaving the pigment more matte, possibly to give the effect of shading.

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Left: Ar 5655.167 in raking light, showing the scoring lines used to map out the design; Right: Ar 5655.156, showing both shiny and matte media on the black horse.

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Mounting the Ar 5655 folios.

After treatment, the Mamluk folios were secured in window mounts using T-hinges made from Japanese sekishu paper adhered with wheat starch paste. The folios will be on display alongside other treasures from the Chester Beatty collection, in the exhibition ‘Gift of a Lifetime’ (19th October 2018—28th April 2019). We do hope you’ll come and see it!

Alice Derham, Heritage Council Intern in Conservation

Celebrating the 50th anniversary of Sir Alfred Chester Beatty’s magnificent bequest, Gift of a Lifetime (19 October 2018 – 28 April 2019) presents a choice selection of masterpieces from this unique collection. You can find out more about some of the treasures in the exhibition here

 

 

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Conserving the Past, Training for the Future: a one day symposium at the Chester Beatty

2018 commemorates the 50th anniversary of Chester Beatty’s death and to mark the occasion a programme of events are being held across the year, including a day-long conservation symposium,  celebrating the conservation internships at the Chester Beatty.

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Conserving the Past, Training for the Future, Symposium at the Chester Beatty Library, June 2018.

Having been an intern at the Chester Beatty from 2014-2015, I know how valuable the internship programme can be for emerging conservators. I was delighted that I was able to attend the symposium, which included a tour of the studio. Here we had the chance to meet all of the past interns that were able to attend, the current intern Alice Derham, as well as Kristine Rose-Beers and Julia Poirier to see the projects they have been working on.

The symposium began with a warm welcome from Jessica Baldwin, Head of Collections and Conservation. Jessica opened the Conservation Department at the Chester Beatty in 2003, and hosted the first conservation internship in 2005. By 2006, the programme was co-funded by the Heritage Council. This short blog will run through the talks presented during the symposium on Friday 8th June 2018.

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Louise O’Connor, now  Conservator at the National Library of Ireland (NLI) became the first intern at the Chester Beatty in 2005. Her talk ‘Conservation internships: Nurturing an acorn’ guided us through the importance of having internships available to train students and recent graduates to ensure not only their development, but to make certain that the skills needed for the preservation of our collections, continues to be developed. Louise took us back through her career, and it is clear that she has taken from her past experiences to ensure that she is able to provide emerging professionals with a varied and valuable experience. Louise is now one of the hosts for the Heritage Council internship held at the NLI.

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Interns past and present had a chance to catch up after the symposium on our wonderful roof garden.

The global-scale of conservation and the many different experiences one can undertake was wonderfully described by Elisabeth Randell, who is currently a conservator at the British Library. Her talk ‘Conservation in motion’ explained how gaining experience in several different heritage institutions in Canada, Ireland and the UK, helped her to discover the pathway she wanted to take, which was ultimately in paper conservation. Being exposed to different collections and methodologies in different countries has given Elisabeth a varied experienced.

After lunch in the sunshine, Kristine introduced the afternoon session. The first speaker was Rachael Smith, Drawings Conservator at Royal Collection Trust, Windsor Castle. She discussed a recent intensive project where she conserved a large collection of Indian paintings and manuscripts on paper. Having worked with similar collections at the Chester Beatty, Rachael detailed the conservation treatments and mounting systems used for this project. It was interesting for Rachael to share her experience during her time at the Chester Beatty, which clearly helped to develop her understanding of Indian collections. Her work at Royal Collection Trust can be seen in the Splendours of the Subcontinent: Four Centuries of South Asian Paintings and Manuscripts exhibition at the Queen’s Gallery, Buckingham Palace, London. The project has also expanded to gallery talks, a news feature on BBC London and a short film about the work undertaken, which can be seen here.

In November 2014, Bevan O’Daly undertook a placement at the Chester Beatty to carry out condition assessments and assist with gallery rotations of textile collections with Karen Horton (Textile Conservator). Bevan’s motivation, hard work and enthusiasm for the textile conservation field has led her to her current post as Textile Conservator at the National Trust, after completing a Master’s in Textile Conservation at the University of Glasgow in 2017. Her talk ‘How long is a piece of string’ was given by the only non-paper conservator of the day where she discussed the many non-textile materials she has encountered during her time in the field alongside the variety of objects she has treated in the past year.

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Fiona McLees presenting the final paper at the Conservation Symposium.

The last talk of the day was given by Fiona McLees, Paper Conservator at the Bodleian Library, University of Oxford, who was an intern at the Chester Beatty from 2011-2012. Fiona’s talk ‘Beyond paper: Mummy bandages & sticks of rock’ highlighted the range of work and the variety of objects that can be included in a paper conservator’s remit. From acting as a courier to international institutions to install works of art for display to running a workshop for children about conservation, details the range of responsibilities for the professional.

The day of lectures was incredibly insightful; having worked with Bevan during my time at the Chester Beatty, and Rachael in my current post at Royal Collection Trust, it was pleasing to see the accomplishments of my former and current colleagues. I was delighted to meet the previous interns I had not yet met and to discover more about their experiences and achievements. Similarly, it was a pleasure to catch up with my former colleagues and friends from both the Chester Beatty and other institutions in Dublin.

JessicaI would like to say a special thanks to Jessica for the enormous effort she has put into establishing this internship program. Jessica’s own experiences have enabled her to ensure that interns working at the Chester Beatty have a good team of mentors around them and a healthy and happy life living in Dublin.

I would also like to extend my thanks to Kristine, Julia, Alice and all of the other CB staff who helped to organise such a fantastic day.

Puneeta Sharma, Assistant Drawings Conservator (Prints and Drawings), Royal Collection Trust

Current Chester Beatty intern in Conservation, Alice Derham, will be giving a lunchtime lecture as part of Heritage Week on Wednesday 22nd August at 1:00pm, Intricate Indian Miniatures through the Eyes of a Conservator. Please join us if you can!

Conservation Internship 2018 – Call for applications

The Heritage Council and the Chester Beatty Library are pleased to announce a twelve-month internship in book and/or paper conservation. The scheme is co-funded by the Heritage Council and the generous support of the Library’s Patrons. The internship offers the opportunity to gain professional workplace experience within a prestigious institution.

This year we had the opportunity to catch up with many of the fantastic interns we have had the pleasure to work with over the years at our first Conservation Symposium on 8th June. We look forward to posting a review of this event in the coming weeks.

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Past interns and the current CBL conservation team at the first Chester Beatty Conservation Symposium.

We are always happy to see past CBL conservation interns go on to achieve success in their careers, and we look forward to welcoming a new conservation intern for 2017-18 in the autumn.

If you are a recent graduate (2016-18) of a recognised book and/or paper conservation training programme and you are interested in joining the CBL conservation team then further information and details on how to apply are available to download via this pdf:

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The deadline for applications is Friday 31 August and interviews will be held on Friday 28 September 2018.

Conserving the past, training for the future

Maintaining and preserving the Chester Beatty Collections and making them available for the use and enjoyment of the public is at the heart of our mission. As followers of this blog will know, the museum has a dedicated Department that specialises in book and paper conservation. In June we are hosting a number of special conservation events, the highlight of which is a one-day symposium Conserving the past, training for the future being held at the Chester Beatty on Friday 8 June.

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Former intern, Rachel Sawicki, conserving a Persian concertina album in 2010.

By repairing and stabilising the collections in our care, conservators ensure they can be researched, displayed and preserved for future generations. In 2005, an internship programme was established to train and mentor newly-graduated conservators, generously funded by the Chester Beatty Patrons and the Heritage Council. There is currently no formal conservation training available in Ireland, so the internships offer unique professional development opportunities for newly-qualified Irish and international conservators. The Heritage Council’s internship programme has evolved over the past 12 years, and is currently run in partnership with four other leading cultural institutions.

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Bevan O’Daly working at the National Trust Textile Conservation Studio, U.K.

Internships highlight the significance of collaboration, cross–generational skills-sharing and international networks, which are all hallmarks of the conservation profession today. The central theme for the European Year of Cultural Heritage 2018 in Ireland is Make a Connection and the Chester Beatty has organised this one-day symposium as a direct response. This public event will highlight the positive influence the scheme has had on the conservation profession’s network in Ireland, across Europe and beyond.

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Fiona McLees conserving a mezzotint in 2012.

Over twenty interns and placement students specialising in book and paper conservation have been mentored by the staff at the Chester Beatty. Their developing careers have led them to work at leading institutions around the world including the National Gallery of Ireland, Trinity College Dublin, The Tate, V&A, Imperial War Museum, Royal Collection Trust, Bodleian Library, National Trust and the National Libraries of Ireland, Sweden and Australia to name but a few.

For this symposium we have invited five of our alumni to return and present insights into the impact the internship has had on their career and the new challenges they face caring for these extraordinary collections.

The symposium is free to attend, but limited places are available, so booking is essential. We hope to see you there!

Mirror of the World: Disbinding an early printed copy of Katib Çelebi’s Cihan-numa

In current conservation practice, where minimal intervention is favoured, it is unusual to decide to disbind a book entirely. However, in the case of the Chester Beatty Library’s rare complete copy of Katib Çelebi’s Cihan-numa (Mirror of the World, CBL AA 306) it was decided that this was the best option in order to carry out a comprehensive conservation treatment of the damaged text block. The Cihan-numa was printed by Ibrahim Müteferrika in Constantinople in 1732, and summarised Ottoman geographical knowledge of the time. It was one of the first texts to be published by Müteferrika, founder of the first official Ottoman printing house in Turkey.

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CBL AA 306 before conservation: the spine, upper board, and opening characteristics of the bound volume.

The book first came to the attention of the conservation department in 2016 when an image of a double folio map was requested for inclusion in the Director’s Choice publication. Due to the restrictive 19th century binding and modern European sewing structure, the opening of the text block was extremely restricted. The text block was already detached from the case binding, and digitisation of the printed map was not possible in situ. In order to facilitate digitisation, the map was removed from the damaged text block so that it could be fully repaired by previous Heritage Council Intern Cécilia Duminuco before digitisation.

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Removing f.196 in 2016, and the conserved map of present-day Iran, Pakistan and Afghanistan after repair.

It was at this point that I was given the project to work on. One of the most significant factors contributing to the decision to take the text block apart into quires was to allow for complete repair. In particular, the green colour used to paint the frame lines around many of the printed maps had gradually burnt through the paper causing most of the folios to split along this line. Resewing the folios in a more sympathetic style would release the strain on the heavily burnished paper of the text block and reduce the risk of any additional breakage in the areas that were decorated with this copper-containing pigment. Using a traditional Islamic sewing style would also be less restrictive than the heavily glued-up 19th century structure, increasing the opening of the text block and allowing the folios to be viewed right into the gutter edge.

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The recto (left) and verso (right) of f.86 showing the extent of breaks caused by copper corrosion.

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Detail of f. 297 before conservation.

While taking apart the text block every detail that could provide information about the original sewing structure was recorded. In the middle of most quires remnants of a pink or red sewing thread and previous sewing stations could be recorded.

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Evidence of original sewing stations on f.126r- 125v (left); and a detail of the preserved pink sewing threads in the gutter of f.125v (right).

It was also apparent that the text block had not been completely resewn, as previously thought. Instead the back of the text block was sawn into at nine stations and cords were embedded inside these recesses over the previous sewing structure. After which a generous amount of glue was applied before gauze and paper linings were added by the 19th century binder. This treatment ensured the quires would stay together, but also restricted the movement of either the sewing threads, or the heavily burnished paper.

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Removing the paper and gauze spine linings from the paper text block (left); manually removing the heavy glue accretions (top and middle right); and the spine after glue removal (bottom right).

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Detail of the nine sawn-in stations and cords.

The gauze and paper backings and the proteinaceous glue were removed manually with a scalpel in order to avoid distorting the highly water sensitive paper with moisture from a poultice. After removing the glue, the quires were separated from each other. Although there was no glue holding the quires together anymore, they did not separate very easily- especially where the paper was sawn into. Great care was necessary to avoid further damage to the paper in those areas. While separating the quires a collation map was prepared in order to chronicle the sewing structure, but which was also used to record any common traits or unusual details found during the process of disbinding. The collation map includes notes of the folios with hand coloured maps, the location of annotations made by someone studying the text in the past, as well as specific damages such as old repairs, damage by insects and copper corrosion.

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Separating the text block into quires (gatherings of folios).

After separating the folios they were put into tissue folders and placed in temporary storage boxes to await their paper repairs. The paper repairs are now well underway and will be the focus of a future blog post towards the end of the year.

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Dorothea separating the text block into quires (gatherings of folios).

Dorothea Müller, Heritage Council Intern in Conservation

Dorothea will give a talk about this project as part of Heritage Week in August 2017. Her presentation will take place in the Lecture Room at the Chester Beatty Library, at 1.10pm on Thursday 24th August.

Delving into Russia – Conservation for Digitisation

The Library is currently working with scholars from the Saint-Petersburg State University in Russia, on the production of a facsimile of our seventeenth century manuscript of The Life of Alexander Nevskij (CBL W 151).

The manuscript contains the Russian version of the mythical exploits of Alexander the Great written in Russian Church Slavonic. It is illuminated with 73 drawings in pen outline and colours. Alexander appears clean-shaven and is often seen riding a unicorn. On the pages, he battles fearsome creatures like the medusa, centaurs, hybrid dog-headed men and other fantastic beasts in far off lands. Another part of the manuscript, containing a copy of the Tale of the Rout of Mamai, is housed at the British Library in London (Yates Thompson ms 51).

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CBL W 151, f.39v-40r after conservation

The text and miniatures will be published as a volume in the series, “Written artifacts of Russian History and Culture, stored in foreign libraries and archives.”

To facilitate this work the complete manuscript has recently been digitised, but before that could happen, the manuscript required conservation.

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The manuscript’s 20th century binding; f.12-13 before conservation showing the restricted opening characteristics.

The manuscript is bound in a modern brown calf binding, most likely added at the beginning of the 20th century. The binding was very tight and prevented the book from being opened fully, causing the folios to curve steeply, and leaving areas of each page obscured at the spine-edge.

In order to increase the opening of the manuscript, whilst still retaining its most recent binding, the book was gently eased open. This simple but careful treatment required the book to be opened slowly page-by-page from front to back. This was done three times to ease the binding sufficiently to facilitate digitisation of the inner most spine-edge margin.

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Dorothea gently working through the manuscript to ease it open.

In addition some edge repair of the folios was necessary to make the digitisation process easier and safer. The paper textblock is very soft and many pages had tears along the edges. The manuscript had been extensively repaired in the past, with Western and Japanese paper. In some places these older repairs had partly detached, especially where close to the spine-edge.

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f.117-118 before (left) and after conservation (right)

A decision was made to leave these old repairs in place and they were reattached where they were at risk of being lost entirely, especially along the spine fold. Edge repair was then carried out with acrylic-toned Japanese Kozo paper and wheat starch paste.

With the binding eased, and the textblock stabilised, the manuscript could be digitised. The book was put onto a cradle with an angle of approximately 110° and the camera lens was positioned parallel to the pages of the book.

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Positioning the manuscript in the digitisation cradle. The folios are carefully leveled to align with the camera.

To further reduce handling, the book was digitised in two stages; firstly the recto pages were photographed, and then the verso. The pages of the book were held in place with polythene tape as necessary. When first assessed it was thought to be unlikely that the manuscript could be successfully digitised without extensive and interventive treatment. It was rewarding to see that the simple easing of the binding permitted the digitisation of the inner most spine-edge margin. The edge repairs prevented any further tears to the paper and safe handling by the photographic services team enabled us to digitise and eventually share this remarkable text. Slide5.JPG

Dorothea MüllerHeritage Council Intern in Conservation

Wishing everyone a very happy St Patrick’s Day from all at the Chester Beatty Library.

Goya on the Go: Lending The Disasters of War

A selection of forty prints from the Chester Beatty collection have just gone on display in Belfast as part of an in-focus exhibition, Francisco Goya: The Disasters of War, at the Ulster Museum.

In September I started work on the preparation of this iconic series of prints. The Chester Beatty holds a complete Second Edition of The Disasters of War (Los Desastres de la Guerra) by Francisco de Goya (1746-1828). Formed of eighty aquatint prints, the series was first produced around 1820 and later printed in Madrid in 1892.

The prints were originally kept as a bound album. However, at some point in the past century the prints were removed from this format and mounted individually in window mounts for display. As the mounts were slightly too small for the prints, they had come in contact with the gummed linen tape used to assemble the mounts and in a number of cases the prints had adhered to the mount board, probably as a result of excess moisture applied during mounting. Apart from this, the paper support and media were in good condition, with only slight planar distortion in the printing plate area.

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Print before treatment: The mount is too small, and the object is in contact with the gummed hinge tape; During conservation: Lifting a print which was adhered to the gummed tape and the mount board.

Elisabeth Randell, a student in Paper Conservation at Camberwell College of Arts in London, started the conservation treatment of these objects during her summer placement with us. First, Elisabeth removed the prints from their unsuitable mounts, before gently surface cleaning them using chemical sponge and erasers as necessary. Old hinges were then removed using locally applied moisture. Edge tears were repaired as necessary using Japanese tissue and wheat starch paste.

I continued the preparation of the prints by adhering new Japanese paper hinges to the upper edge of the folios using wheat starch paste. New conservation-standard window mounts were then prepared, and the prints were carefully secured in the mounts using Japanese paper T-hinges. This allows the prints to be turned so that the verso can be viewed without incurring any damage.

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During conservation: Securing the conserved folio with new Japanese paper T-hinges

During my work on the prints, I was also assisted by Adam Macklin, a student in Book and Paper Conservation at the University of Amsterdam, who volunteered at the Chester Beatty Library for one week. Adam’s help was invaluable at each step of the mounting process, and ensured the work was completed on time.

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After conservation: a conserved and mounted print, ready for exhibition. During conservation: Adam working on securing the prints in their new mount.

Finally, I assisted with the packing of the objects for travel. This included the preparation of six conservation-grade phase-boxes, the proper wrapping of the objects, and finally packing the crate for safe transport. The 40 prints to be exhibited were then transferred to the Ulster Museum, where they were framed by Conservator Gillian O’Neill and her team. Once framed, Julia Poirier and I travelled to Belfast to oversee the installation of the prints in the Ulster Museum’s print gallery.

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Loading the crate for travel; and packing the crate with the objects and protective foam.

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Installation at the Ulster Museum.

Thanks to this amazing project, I now have a much better understanding of the complete loan process in an institution. Working with different stakeholders was highly enriching, and taking part in the installation of the exhibition in at the Ulster Museum in Belfast was a great reward.

Cécilia Duminuco, Heritage Council Intern.

Francisco Goya: The Disasters of War will open on the 25th of November 2016 and will run until the 4th of June 2017.

Internship in conservation

The Heritage Council and the Chester Beatty Library are celebrating the tenth anniversary of the conservation internship scheme. We are pleased to offer a twelve-month internship in book and/or paper conservation.

The scheme is co-funded by by the Heritage Council and the generous support of the Library’s Patrons. The internship offers the possibility of professional workplace experience within a prestigious institution.

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Cécilia Duminuco, carrying out pigment consolidation as part of her internship.

The successful candidate will gain experience working in the Library’s busy Conservation Laboratory. He/She will work under the supervision of the Library’s Senior Conservator, Kristine Rose Beers. Practical projects will be assigned to fit in with the Library’s on-going treatment, exhibition and loan programmes and include the preparation of manuscripts and single folios for digitisation from across the collections.

How to apply:

If you are interested in joining the CBL conservation team then further information and details on how to apply are available to download here.

You can learn more about the experiences of previous interns here.

Shared experiences in Copenhagen

In April, I had the chance to fly to Denmark to be part of the 16th International Seminar on the Care and conservation of manuscripts, which was held in Copenhagen from the 13th to the 15th of April, 2016. It took place in the Faculty of Humanities at the University of Copenhagen. During the three days of the conference various topics were debated, from preservation and conservation case studies, to digital imaging and bookbinding history.

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The Faculty of Humanities, Copenhagen University.

The quality of presentations was very high, and it was difficult to choose a favourite. Going through my notes, I selected the ones that particularly raised my interest; Michaelle Biddle’s talk about her work in Nigeria, and Marco di Bella and Nikolas Sarris’ presentation about the conservation challenges they faced in Ethiopia were both fascinating. Their creativity carrying out conservation treatments in a less than ideal environment was admirable.

Bookbinding history was well illustrated by Frederick Bearman’s talk on laced overband bindings, and Abigail Quandt’s research on purple-dyed parchment manuscripts. I also learned a lot about digitisation and its possibilities for conservation purposes through, Alberto Campagnolo’s presentation. He demonstrated his PhD research in creating a digital model of the collation of bookbindings. Multi-spectral imaging was also discussed in Michael Toth’s presentation and demonstration.

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Marco di Bella and Nikolas Sarris’ presentation,“The conservation of a 15th-century large parchment ms of Gädlä säma ‘tat from the monastery of Ura Mäsqäl: Further conservation experiences from Easty Tigray, Ethiopia.”

Finally, I greatly enjoyed Matthew Collins talk about the York biomolecular study of parchment. Using a non-invasive rubbing technique, the York laboratories have managed to extract DNA from old parchment, therefore enabling the study of the animals (such as their species, age, size, etc.) used to create writing supports.

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Presenting my paper with prof. Lieve Watteeuw, “Sewing threads in hand-made West European bookbinding: Historical sources, imaging and analytical assessment (12th– 19th century).”

On the final day of the conference, I also had the privilege to present my MA research project in collaboration with Professor Lieve Watteeuw (KU Leuven, Faculty of Arts, Illuminare – Centre for the Study of Medieval Art). Our presentation, “Sewing threads in hand-made Western European bookbinding: Historical sources, imaging and analytical assessment (12th -19th century)”. It was a wonderful experience and I was delighted to be able to share the results of my MA research with the audience, a subject you can read more about in my previous blog post here).

Attending the conference was also an amazing opportunity to meet other professionals in the field and to discuss conservation! Finally, on the last day of my trip, I even had a few hours to discover how beautiful Copenhagen is.copenhagenThe conference was a huge success, with approximately 220 participants from all around the world. I hope I will have the chance to go back to Copenhagen soon, and attend the next “Care and conservation of manuscripts” conference in April 2018.

Cécilia Duminuco, Heritage Council Intern.

A tale of twisting threads

With this post, we’d like to take the opportunity to welcome our new intern, Cécilia Duminuco. As we mentioned back in May, our internship programme is celebrating its 10th year, and we’re very happy that Cécilia has joined our team in this anniversary year. We hope you enjoy hearing about Cécilia’s work prior to joining the CBL Conservation team.

Before starting my internship at the Chester Beatty Library this November, I completed an MA research project at West Dean College, University of Sussex, in the U.K.

My research developed in collaboration with the Heritage section of the Maurits Sabbe Bibliotheek at the Catholic University of Leuven (Theology Faculty) in Belgium. I studied the sewing threads and sewing structures of twenty-four manuscripts and printed books from Western Europe, ranging from the 12th to the early 19th century, by means of two methods: visual assessments and Reflectance Transformation Imaging (RTI) with a Microdome, a digitisation tool created by the Catholic University of Leuven.

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Figure 1: the Microdome. Credit: Marc, P., Vandermeulen, B. & Watteeuw, L. (8/09/2014) “See the Surface. Imaging and measuring surface characteristics of library materials by photometric stereo (RICH Project)”, Digital Humanities@Arts Summer School, Leuven, p.8

In this post, I will briefly present the Microdome, the imaging technique attached to it and the results of the sewing thread analysis with this apparatus.

Reflectance Transformation Imaging (RTI) is defined by the Cultural Heritage Imaging organisation as “a computational photographic method that captures a subject’s surface and colour and enables the interactive re-lighting of the subject from any direction. RTI also permits the mathematical enhancement of the subject’s surface shape and colour attributes. The enhancement functions of RTI reveal surface information that is not disclosed under direct empirical examination of the physical object”. The technique was invented by Tom Malzbender in the Hewlett-Packard Laboratories in 2000-2001. In 2005, following Tom Malzbender and the Cultural Heritage Imaging organisation’s previous research, a new imaging device -a Portable Light Dome (PLD) – was developed in the Catholic University of Leuven.

The Portable Light Dome (PLD), also called Microdome, is a dome-shaped tool including two hundred and twenty eight LED white lights of four thousand Kelvin. A high resolution digital camera is mounted on top of the device. The object to be studied is placed in the centre of the dome, and several pictures with different lighting angles are automatically recorded. The images are then processed and viewed with specific software. The viewing software, PLDViewer, allows the researcher to analyse the created image through the use of several tools, such as a zooming and rotating functions, a measurement tool, and a 3D model exportation tool. This technique allows the surface characteristics of an object to be studied precisely, non-invasively. Furthermore, several filters can be applied to the image, allowing the creation of enhanced views of the surface (such as the Sharpen or the Shaded filters).

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Figure 2: Ambient light source and Colour filter, with light positions. Cod.4, pp.4-5.

Using a survey, I carried out visual assessment of each book’s sewing structure, before applying Microdome imaging on two pages of each book where the sewing threads were visible.

Fig3

Figure 3: Albedo light source and Shaded exaggerated filter, with light positions. Cod.4, pp.4-5.

In bookbinding, a sewing thread is defined as “a filament or group of filaments used for securing the leaves or sections of a book.” These filaments or fibres are most commonly of natural origin; sometimes from animal sources, such as silk and wool, or plants such as flax, hemp and cotton. Fibres were traditionally harvested by hand, and according to their nature they were subjected to different processes such as cleaning, combing and twisting before spinning. This is what results in each thread’s unique characteristics.

Thread twist count

The twist of a thread is defined as the “turns per metre of yarn, used to hold filaments together”. The number of thread twists per centimetre was analysed for forty-six thread samples using the measuring tool -a one-millimetre wide vertical or horizontal grid applied to the images.

Fig4

Figure 4: Twist count, Ambient light source and Sharpen filter. INC 805 EF_Etym, gathering beta.

Regardless of their date, the majority of the threads have approximately five to eight twists per centimetre (t/cm). In nine of the books, thread samples examined showed a consistent twist number range per book. However, in eleven books, the sewing threads had different twist numbers in each of the various samples analysed.

Fig5

Figure 5: Twist count, approximately 6t/cm. PBM 248.158_Hens Viri, pp152-153.

Twist angle

The twist angle is defined as “the amount of twist in a yarn measured in degrees”. The images of forty-eight sewing threads were studied after enhancement. In order to calculate the angles trigonometry formulas were applied by measuring the thread thicknesses (the opposite side of the right triangle) in combination with the twist measurements (the hypotenuse).

Fig7

Figure 7: A right-angled triangle ABC.

Fig6

Figure 6: Twist angle (A) measurements. Cod.4, p4-5.

All of the sewing thread twist angles measured ranged from 15° to 36°, with fourteen threads presenting a twist angle ranging from 20° to 25°. The smaller twist angles did not appear to be characteristic of a certain time period. However, the higher twist angles (more than 30°) were more commonly found in books from the 16th to the 19th century. It should also be noted that when considering threads in one volume, twist angles may vary widely. However, the majority of the threads studied presented relatively similar twist angles, within a narrow range.

Fig8

Figure 8: Twist angle measurements. PBM 248.158_Hens Viri, average ~23°, pp.152-153.

Thread thicknesses

Using the Microdome software measuring tool, thread thicknesses were also calculated in the samples. The majority of the sewing threads (forty-one samples) have an average thickness ranging from 0.40 to 0.80 millimetres. Five threads, from the 17th to the 19th century, are thinner than 0.40 millimetres; and twenty others, with no specific time range, have a thickness ranging from 0.50 to 0.65 millimetres. Twelve threads, nine of them from the 16th century or earlier, are thicker than 0.65 millimetres. Within a single book, sewing thread thicknesses vary. Similarly, within a single thread sample, variations in thicknesses can be observed

Fig9

Figure 9: Thread thickness measurements. INC 805 EF_Etym, average ~0.60mm, centre of gathering alpha.

In conclusion, all of the features studied revealed variations in the sewing thread structures. It seems likely that these variations could be explained by the hand-processing of the threads that were used.

A Picardy wheel. Engraving from Arts et Metiers, l'art du fabricant d'étoffes by J.M. Roland de la Platière, ~1780

A woman spinning fibres on a Picardy wheel. Engraving from Arts et Metiers, l’art du fabricant d’étoffes by J.M. Roland de la Platière, ~1780.

Analyses of these results has allowed me to define the advantages and limitations of both visual and analytical techniques for assessing books. In particular, the complimentary use of these two methods served to highlight the possibilities offered by the Microdome for use in the conservation field.

More details about the Microdome and my research will be presented at the Care and conservation of manuscripts conference in April 2016 in Copenhagen.

I am very grateful to Professor Lieve Watteeuw and to the Maurits Sabbe Bibliotheek of the Catholic University of Leuven who gave me such a wonderful opportunity to work with one of the most promising digitisation tools in the conservation field.

Cécilia Duminuco, Heritage Council Intern in Conservation