Post by Claire Dantin, Conservation intern 2016-17

(NLI’s conservation internship is jointly funded by the Heritage Council)

For a conservator, understanding the original materials of an item before any conservation treatment is essential. I recently conserved 4 albums containing beautiful prints and drawings of Irish castles by James Stark Fleming (1834-1922). Some of the earliest depictions of Ireland’s built heritage and landscape are found in these albums in the Library’s Prints and Drawings collection.

At some point, Fleming’s drawings were assembled into these albums, possibly by the artist himself. However poor materials and an unusual book structure meant the albums were very fragile and degraded. It was therefore important to conserve the album and not just the drawings within.

ALBUM STRUCTURE

A traditional binding is based on several sections of folded paper sewn together with thread. These 4 albums have a very different binding structure; instead of folded papers sections, there are guards hinged to pages with textile. The guards and the pages are made of very thick stiff card.

Unusual binding structure of the albums, before conservation treatment

 

There is no sewing; layers of thin textile and paper were then applied with animal glue to edges of the guards to form a spine. The front and back boards are attached to the spine by the lining. This structure is in fact more similar to photograph albums which were commercially available from the 1850s.

Diagrams showing the structure of one album ‘section’ and these sections assembled with a spine lining.

 

CONDITION

During conservation; securing the album structure with pamphlet style stitching

 

The albums were in very poor condition. The binding structure was made from poor quality materials. These were now acidic and brittle – a common issue for 19th century items. Handling created further damage. The drawings within were discoloured due to contact with acidic pages of the albums.

Following documentation, the challenge began to preserve the working parts of each album, while intervening in the most appropriate way. My conservation treatments aimed to enable safe handling of the items during the digitisation process and for future consultation or exhibition.

CONSERVATION

Adapting the binding structure

The structure of the album was the main reason for its decay. One album (TX2) required an interventive treatment approach. Its spine was completely detached, the textile hinges were torn and brittle and many pages were loose or detached.

I applied a treatment solution that respected the original structure and materials of the album. The textile hinges were delicately removed with a scalpel and replaced with a 100% unbleached cotton textile, its strength and thickness matching the original textile. The acidic spine lining was removed and replaced with flexible Kozo paper linings. The heavy boards were attached with a strong yet thin textile. The text block was then secured with a pamphlet style stitch, sewn through every two sections of the replaced textile hinges (fig 4).

Flattening distorted pages

Distorted album pages and a diagram of the humidification ‘sandwich’ created to flatten them

 

The condition of another album (TX1) was rather unusual as it had distorted pages. The adhesive used to apply the drawings had caused the album’s pages to distort.

As a treatment solution I introduced enough moisture vapour to the album’s pages to relax the papers fibres and adhesive layers. As the binding was intact, this meant I needed to create humidification ‘sandwich sleeves’ to slip over the albums pages. The pages were then gently dried under pressure to flatten the album pages. I gradually worked through the volume, by systematically humidifying and pressing each page until it was all flat.

Brittle papers

The album’s pages, made from wood pulp paper, were so brittle the edges had snapped. To make the pages strong enough to be turned, I infilled the losses with several layers of Japanese papers orientated in different fibre directions. I then gently rounded the edges of the repairs to match the original pages (fig 5).

The conserved albums are now stored in a bespoke archival box and digital images are on the Library’s online catalogue. With the stabilisation of the binding structure, the book can be handled and opened easily without further damage.

Brittle album pages before and after conservation treatment

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Post by Heraldic collection conservator Louise O’Connor

Science plays a central role in modern conservation of cultural heritage. By understanding the chemical structure of materials, a conservator can document the condition and potential degradation of historic objects, as shown in our last post. Now we’d like to show how conservators address damage in heraldic manuscripts through conservation treatment, making them accessible for digitisation.

To treat or not to treat 

Once damage to the manuscripts is identified and documented, conservators evaluate potential treatment options. The condition of the heraldic manuscripts prioritised for treatment was complex; tight bindings, corrosive iron gall ink, fragile pigments and many disfiguring stains and old repairs. A conservator’s decision-making process considers not only the chemical degradation of the object, but also its historical integrity. In collaboration with our library colleagues, the object’s function for today’s user is also considered prior to treatment. Ethically, conservation treatments follow the principle of minimal intervention, similar to the concept of ‘first do no harm’. The choice of materials and techniques follows the idea of ‘retreat-ability’. The choice to intervene is never taken lightly, yet given the immense fragility of the heraldic manuscripts – treatment was urgent.

 Selecting a conservation treatment

By consulting the collected body of conservation research, the treatments we choose for the heraldic manuscripts included disbinding, removal of surface dirt, chemical stabilisation of iron gall ink with calcium phytate process, removal of disfiguring stains and old repairs, pigment consolidation, tear repair and loss infill, and applying a conservation binding. Each unique manuscript was treated individually and we documented all processes. Here we show some of the steps from these conservation treatments, which resulted in an easily legible manuscript, preserved for present and future generations of the curious.

Treatments – step behind the scenes

The manuscript was first removed from its damaging binding. This involved removing degraded layers of glue and textile from its spine. Proteinaceous adhesives react to moisture. Applying a water-based poultice to the glue, allows it slowly absorb the moisture. As the adhesive film starts to swell, it’s possible to mechanically remove it from the paper. As the adhesive rehydrates it also stinks to high heaven!

 

Grey dirt particles, loosely held to the surface of the paper by intermolecular forces, were removed by gently rubbing a soft eraser across the paper’s surface. This improves both the look and feel of the manuscript. The ink is not affected by this action; and utmost care and skill is needed to surface clean very fragile surfaces, such as mould damaged papers.

The ink was then tested for iron components. Indicator papers impregnated with a dye confirmed the presence of soluble iron 2 ions in the ink. The paper turns pink if it’s a positive result.

Washing paper removes acidic degradation products and reforms the hydrogen bonds of its cellulose structure, making it stronger. The paper sheets were floated in a sequence of specially prepared aqueous solutions.

After a few minutes, chromophores, which cause paper to discolour, solubilised into the bath water. The calcium phytate treatment cycle converted the remaining ink Fe 2 ions into a stable chemical state and increased the pH of the paper.

While the folios were slightly humidified, old paper repairs, previously held in place with starch or protein glues that have solubilised, were gently removed inch-by-inch. This task is a precise skill, too much tension and original fibres can be disturbed.

Paper folios with pigments are very delicate. Damaged pigment layers were secured using a dilute cellulose ether consolidant. Using magnification, it was applied locally to the affected areas using a thin brush or with a nebuliser as an aerosol.

Removing discolouration from paper with colours is a delicate and precise treatment. The sheets cannot be treated in a bath, as the pigment could be damaged. Instead, moisture was applied to the areas of discolouration using a rigid hydrogel. The gel was made from a polysaccharide derived from seaweed. It was cast into sheets and cut to the size of the stained area. The soluble discolouration diffuses into the gel through capillary action of water.

 

Tears and losses in the papers were repaired and infilled on a light-box. This transmits the light through the paper, making it easier to see the damaged areas. The folios were then guarded into new sections for a new conservation binding.

Rebinding the manuscript volume was chosen to keep its historic integrity and its place in upright storage of the collection. The new conservation binding structure is a creative and skilled solution for the manuscripts. It has the look of an 18th century binding yet it also has a flexible spine and no adhesive. This means the binding can be easily reversed in the future. The new binding opens flat and this allows easy viewing of the manuscript folios for digitisation.

Though selective conservation treatment, the Heraldic Manuscript Conservation Project reduced the risk of damage to fragile and deteriorated folios. New information gathered during the treatments give greater understanding of these unique cultural items. These valuable manuscripts are now freely available online to researchers world-wide.

 

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The conservation project (2015-2017) was supported by the Department of Heritage, Culture and the Gaeltacht.

 

Project conservators: Elodie Leveque, Noureen Qureshi, Elizabeth Randell, Claire Dantin.

 

Heraldic collection conservator: Louise O’Connor

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Post by Heraldic collection conservator Louise O’Connor

All organic materials degrade. Historic manuscripts are handmade, unique artefacts combining parchment, paper, animal glues, pigments, inks, threads and leather. Unless left untouched in an oxygen free environment, these components may lose strength, discolour and can fall apart!

Treating unique and degraded manuscripts can be a key part of a digitisation project. Over the last 4 years, in a project  supported by the Department of Culture, Heritage and the Gaeltacht. the NLI team has been working to make 17th century heraldic manuscripts available for free online. These manuscripts come from the collection of the Office of the Chief Herald. They are part of a tradition of heraldry that originated in the medieval period, to regulate armorial bearings, or “coats of arms”, originally used to identify people on the battlefield and later to attest documents and indicate ownership. For a system of identification to be effective, it requires regulation – the use of the same arms by more than one person would result in confusion. Specialists, known as heralds, were needed to keep the necessary records and advise on all related matters, and this tradition continues at the National Library of Ireland to this day.

As part of this project, conservation treatment of damaged and delicate manuscripts was required to facilitate digital photography. Scientific visual investigation is key to understanding the physical chemical and biological ageing of materials. Let’s take a closer look at manuscripts through the eyes of a conservator:

Heraldic manuscripts with drawing of wyvern (dragon-like creatures) supporters; the binding is tight and hides the drawing (GO MS 31)

A binding is a mechanical object; it should open and close and is the sum of its parts. The heraldic manuscripts were poorly bound or restored (‘rebacked’) with too much protein based adhesives on the spine from the 19th century. Hot animal glue was used for centuries by bookbinders. It has strong adhesive properties, but will quickly degrade; shrinking and crosslinking. This prevents the binding from opening and means that readers can no longer see drawings and script along the inner edge.

Paper is an organic cellulose material. The paper in the heraldic manuscripts dating from the 16th and 17th centuries was hand-made using linen and cotton rags, from items such as old ship sails and old underwear. In fact, wonderful papermakers’ marks, known as watermarks, can be seen in the sheets with transmitted light (images recorded on ‘Watermarks Irish Documents project ‘.

Cellulose is a linear polymer. Acid catalysed hydrolysis of the cellulose polymer causes the polymer chains to break resulting in weak or brittle paper). It also degrades by oxidation, especially if exposed to light or excessive airflow. Oxidation forms carbonyl groups called chromophores which give degraded paper a distinctive yellow colour. Old manuscripts even have a distinctive smell.

Paper is organic and degrades by oxidation and hydrolysis. Dirt particles stick to the paper fibres with weak chemical bonds. (GO MS 19 – before treatment)

 

The heraldic manuscripts were covered in layers of surface dirt as a result of poor storage in the past. Small dirt particles are held to the uneven surface of paper by weak forces, called Van der Waals forces. Dirt particles can transfer from hands during reading, and airborne particles (i.e. dust) will slowly settle on paper over time. Surface dirt particles are disfiguring and abrasive, and will reduce the pH of the paper and catalyse further chemical degradation.

Purple blotches and brown lines are evidence of mould and water damage on historic paper. (GO MS 85 – before treatment)

 

Water can damage paper and it is something to which paper conservators working in rainy Ireland are accustomed! As cellulose molecules have many hydroxyl groups, paper has a high affinity for water. This is why water is used in papermaking and paper conservation (more on that later). Yet, it can take paper a long time to dry out and in this lag time (min 48 hours) mould can grow. Mould eats paper, making it fragile (think damp toilet paper) and very difficult to handle. Historic repairs added the some folios in the heraldic manuscripts, though well intentioned, only compound the difficulty in handling.

Iron gall ink canrust’ paper as it degrades. This is a huge problem, as up until the 19th century, ink made from oak galls was very common in Europe. Homemade recipes combined tannins (from crushed galls), iron sulphate (an ancient material known as copperas or green vitriol) and water to varying amounts. However, the ink corrodes with too much sulphuric acid and free iron (2) ions, in high relative humidity (it averages 70-85% in Ireland).

Ink containing iron can be chemically unstable and damage the paper. (GO MS 85)

 

Iron gall ink corrosion degrades cellulose in stages. Fuzzy ink lines are first noticeable as the iron ions move into the paper. Next the script becomes visible from the back as the iron ions move through the paper. Finally, the ink lines will crack or simple fall out of the paper leaving a lace-like pattern. This leads to loss of valuable text due to significant destruction of the paper along the ink lines.

Colour is an essential element of heraldic art; the use of each colour is symbolic. On manuscripts, ground pigment or dyes were mixed with a water-soluble binder, such as gum arabic and finely applied onto the surface of the paper or parchment. Unlike oil paintings, there is no varnish.

Blue pigment particle loosely held to the paper surface by weak chemical bonds and binder and are easily detached through handling. (GO MS 32)

 

Colour on paper is very fragile. The pigment particles are loosely held to the paper surface by weak chemicals bonds and a thin binder layer which forms a film. In the Heraldic manuscripts, the colours appear opaque and matt due to a low ratio of binder to pigment or high ‘pigment volume concentration’. Cleavage is the term used to describe the break between the paint layer and the paper substrate.

Under magnification, it’s possible to see damage and loss to the red pigment layer. (GO MS 85 – folio 166)

 

Repetitive use, like flexing the paper support, results in the loose pigment particles flaking off. Pigment layers can also turn into powder. This can happen from abrasion.By looking at the pigment layers with magnification, conservators can assess the extent of damage.

Pigments can also dramatically change colour due to chemical changes in their structure. White lead is a pigment made from basic lead carbonate, 2PbCO3·Pb(OH)2. It was used for centuries by artists but was so toxic it was eventually banned. White lead was often used to highlight the flesh tones of figures in manuscript illuminations. It reacts with trace amounts of hydrogen sulphide in the air to produce black lead sulphide. This can impact how researchers read these images today.

Blackening of white pigment, possibly lead white, is visible on the face and arm of the woman in this image. (GO MS 31)

 

Science plays a central role in modern conservation of cultural heritage. By understanding the chemical structure of materials, a conservator can document the condition and potential degradation of historic objects. Have you enjoyed taking a closer look at the heraldic manuscripts through the eyes of a conservator? Find out more on how science helps the treatment of delicate and damaged manuscripts in our next blog post.

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