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.

Slide1

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.

Slide2

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.

Slide3

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

AA306_01_Folio_297_Before_Conservation(4)

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.

Slide4

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.

Slide5

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).

Slide6

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.

Slide7

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.

AA306_2_006_separating_folios (150)

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.

Advertisements

Yasha: A Traditional Japanese Paper Dyeing Technique

The Chester Beatty Library Conservation Department and the Restorient studio in Leiden have been working together closely for years. Andrew Thompson and Sydney Thomson at Restorient have conserved some of the collection’s most important Japanese scrolls and have been extremely generous in sharing some of their expertise with us. Thanks to them we discovered and have adopted the use of yasha, a traditional Japanese dye.

Yasha is the natural yellow-brown dye extracted from cones of the alder tree (Alnus japonica) and it has been used in Japan since the 8th century. In Japanese mounting studios, yasha is still used to dye the lining papers of hanging scrolls and hand scrolls. The light brown colour obtained from the dye helps to soften the white tone of the paper and silk used for linings and repairs.

Slide1

Preparation of  the yasha dye from Alnus japonica cones

Through centuries of practical application, the traditional use of yasha has proven its stability and durability which makes it highly suitable for conservation. Scientific studies confirm that papers dyed with yasha remain pH neutral or slightly alkaline, and retain their brightness and colour on ageing. Most plant dyes are light sensitive but yasha is lightfast, a quality which ensures its continued use.

Like many features of the traditional Japanese conservation studio, yasha is now readily available to Western conservators. With a growing interest in adapting conservation techniques imported from East Asia and Japan, the use of alder cones has become a known technique for dyeing paper when working on Japanese or Chinese Art objects.

The preparation of the dye and its application is straightforward.

Preparation

  1. Cover the bottom of a pot with alder cones and submerge them in water.
  2. Simmer for about 2 hours until the colour intensifies in tone.
  3. Once boiled, leave the dye to cool.
  4. Strain through a silkscreen or muslin cloth to remove impurities. The dye is now ready to use.

Application

  1. Cut a number of Japanese paper sheets of the same size.
  2. Pour the prepared dye into a shallow dish and apply directly to the rougher side of the paper with a large brush on a flat, non-porous surface.
  3. The brush strokes should be light and must follow the grain direction of the paper to avoid stretching the fibres. Each sheet is dyed individually; the dye is brushed on evenly and the surface of the sheet completely covered.
  4. The next sheet is laid on top of the last, staggered by 5mm. Repeat the process to ensure the dye is evenly applied to each piece of paper.
  5. When all the sheets are dyed, lay the stack on felt for 30 minutes to allow the water to begin to evaporate.
  6. After this short drying period the sheets are stronger and can be separated and left to dry fully on felt.

    Slide2

    Application of the dyestuff to handmade Japanese paper.

Fixing

  1. Rinse the dried sheets in cold water for no more than a few seconds as the dye is still fugitive and can be removed in water.
  2. Prepare a bath of water and Potassium Hydroxide (Potash). When the water reaches pH 7.1 rinse each sheet separately in the prepared bath to fix the dye onto the paper.
  3. Dry the sheets on felt before a final rinse in plain water to remove any excess lye (Potash).
  4. When dry, the sheets are ready to use.

    Slide3

    Fixing the dye, and the finished yasha-toned repair paper.

The process of layering the paper in a stack while applying the dye to each sheet of paper, creates a progressive darkening of tones throughout the stack from a light cream to a yellow-brown tone. The first sheet of paper to be dyed will be darkest in colour as the dye penetrates through the stack when subsequent sheets are dyed. The last sheet to be dyed when it is placed on top of the stack will be the lightest in colour, receiving only a single application of the dye.

As the dye is applied, it penetrates into the paper colouring the fibres internally. This is a major advantage when using this paper for repair as the water cut edge is the same colour as the toned surface. Unlike watercolour or acrylic paint solutions, where the application can leave visible brush strokes and tends not to fully penetrate the paper, yasha tones each sheet evenly, regardless of the size of the piece of paper.

Presentation1

A water-cut edge of yasha toned Japanese paper; and an Indian miniature (CBL In 11A.61) repaired using the prepared paper.

The gradation of colour obtained through the layering application technique is also extremely helpful to the conservator as it quickly produces a large quantity of paper dyed with various shades of a similar tone. The repair paper can then be used selectively to match the colour of a single sheet or for the repair of a full volume. The tones obtained from yasha are even and saturated, yet the paper remains soft and flexible and does not stiffen on drying. After fixing the dye no colour shift has been observed when repairs were applied.

The selection of different varieties of alder cones (both Japanese and European) and the preparation method described will achieve further useful colour variations and help the conservator to produce a large array of toned repair papers that can be kept on hand for use as necessary.

Slide2

The wide variety of tones that can be achieved using yasha.

The adoption of the Japanese dye yasha to tone repair papers at the Chester Beatty Library has been a success and we cannot recommend it warmly enough to colleagues. It is a wonderful method for dyeing paper and this readily available material certainly deserves to find its way into every conservation studio.

Julia Poirier, Book and Paper conservator

The Library is very grateful to Andrew and Sydney at Restorient for first introducing us to this versatile dyestuff when Julia undertook a short placement with them in 2013.

This work was first presented as a poster, ‘Yasha – Adapting a Traditional Japanese Paper Dyeing Technique to the Conservation of Parchment and Islamic Paper’ at the IADA conference ‘From Generation to Generation – Sharing Knowledge, Connecting People’ in Oslo, Norway 3-5 May 2017.