Collection Care blog

Behind the scenes with our conservators and scientists

Introduction

Discover how we care for the British Library’s Collections by following our expert team of conservators and scientists. We take you behind the scenes into the Centre for Conservation and the Scientific Research Lab to share some of the projects we are working on. Read more

17 May 2023

Conservation of Maps in the digitisation project: Qatar Foundation Partnership – Part 2

Following part 1 of the Conservation of Maps in the digitisation project: Qatar Foundation Partnership, this second blog post will present the treatments of two maps belonging to the IOR collection of the British Library: IOR/X/10065 and IOR/X/10066. Similar to the maps presented in the first blog post, these maps also have cloth as a secondary support. In these cases, the maps were fragmented and lined on a cloth support which allowed them to be folded (picture 1 & 2). A difference with the first group of maps is that they did not have textile or silk ribbons on the edges.

The IOR/X/10065 map covers in extended detail the river Tigris and its valley in southern Mesopotamia, now Iraq. The map clearly shows canals, settlements and the site of the ancient city of Opis, approximately 45 miles north of Bagdad (Information by Nick Krebs).
Picture 1: IOR/X/10065 recto before treatment
Detail of the IOR/X/10065 map showing four fragments divided by the joints, with cloth as a secondary support.
Picture 2: Detail of the joints (cloth) that allow the folds of IOR/X/10065

These two items had the same main damage. The substrate, a paper lined with cloth, was broken or weakened in various areas of the joints where the maps used to be folded (picture 3 & 4).

Upper part of the IOR/X/10066 map (recto), before treatment. The map covers the River Tigris and associated Katul al Kesrawi and Nahrwan canals in central Mesopotamia, nowadays Iraq from Tekrit, nowadays Tikrit, Iraq. The map focuses particularly on the river and its associated canals with extended details. (Information by Nick Krebs).
Picture 3: Upper part of the IOR/X/10066 recto before treatment
Detail of IOR/X/10065 map during conservation. The four fragments of the map are completely separated due to the broken joints of the secondary support.
Picture 4: Detail of IOR/X/10065 with broken joints

 

The paper support on the IOR/X/10066 map is thicker and distorted, with the distortions possibly caused by its large format and the broken joins no longer creating tension (picture 5). On both maps, there were small paper tears and folds around the edges. There were also loose threads due to the fraying of the cloth along the edges (picture 6). The condition of both maps made handling and digitisation very difficult, especially due to their oversize format, IOR/X/10065 measuring 1014x750 mm and IOR/X/10066 1235x1073 mm.

Upper part of the IOR/X/10066 map (verso), before treatment. The distortion of the map can be seen along the edges of each separated fragment due to the broken joints of the secondary support.
Picture 5: Upper part of the IOR/X/10066 verso before treatment
Detail of the IOR/X/10065 map before conservation. This shows two fragments completely separated due to the broken joints, with loose threads due to the fraying of the secondary support.
Picture 6: Detail of IOR/X/10065 fraying

 

Decision making

The aim of the conservation treatment was to stabilise the items to function in their current role and to ease handling for the next stages of the workflow: cataloguing and digitisation.

For the decision-making process we considered the condition of the maps and their original use, to be folded and unfolded many times when used. In addition, minimal intervention, re-treatability and fit-for-purpose, principles from our guidelines, were taken into account, as well as the 5 hours limit for the treatment of each item.

 

Selecting and preparing materials for treatment

Our treatment proposal was then focused on re-establishing the ability to fold the maps which is convenient for handling and storage. We decided on using a cloth lined with Japanese tissue for the joint repairs, similar to the construction of the maps.

 

Selection of the cloth

A thick Japanese tissue would not be enough to repair areas that are to be folded multiple times. We decided on Aerocotton, a material commonly used by book conservators to reinforce book joints which is a light but strong cloth. The cloth was washed with hot tap water before its use to remove any possible sizing and additives.

 

Selection of the Japanese tissue

We chose an 11g/m2 Japanese tissue with kozo fibers, which is strong and thick enough to give support to the cloth and the tear repairs.

 

Lining the Aerocotton

Aerocotton is difficult to cut after washing, (see picture 7). Therefore, it was lined using Japanese tissue and wheat starch paste (WSP). This helps to stiffen the Aerocotton, with the Japanese tissue working as a support to make it easier to handle and to limit frayed edges. The cloth lined with the paper was left to dry on a wooden board similar to a karibari, to ensure it dried with tension (picture 7).

This image shows two Aerocotton fragments, on the left and right hand sides.  The Aerocotton on the left shows how it looks dried after washing, displaying wrinkle and some fraying on the edges. The Aerocotton on the right shows how it looks dried after lining with a Japanese tissue and using wheat starch paste as adhesive. This fragment looks flat and easier to handle.
Picture 7: On the left Aerocotton dried after washing and on the right lined Aerocotton with Japanese tissue

A second lining of Japanese tissue (11g/m2 with kozo fibers) was pasted to the lined cloth strips, since it reinforced the repairs without adding any thickness. This was carried out again on a wooden board. A plastic strip was placed between the board and the strip. This would function as a barrier and prevent a section of Japanese tissue strips adhering on the board. This way, our second lining dried stretched on the board as it protruded from the plastic strip like it would on a karibari, (video 1).

 

Video 1: Preparing and applying the second lining of Japanese tissue on the lined cloth strips

 

Once the Japanese tissue was dry, we lifted them from the karibari with a bamboo spatula. The plastic strips delimited the area that we used to paste on the map. Finally, we cut them with a water brush so that the edges had a water-cut finish: this gave a stronger attachment to the tear repairs when pasted on the maps, (pictures 8 and 9).

The image shows an Aerocotton strip lined with Japanese tissue on a green cutting mat. On the right of the strip, there is a water brush. This is illustrating process of cutting the edges of the Japanese tissue to create the water-cut finish.
Picture 8: Cutting the edges with a water brush
Close-up of the prepared strips with the water-cut finish on the edges.
Picture 9: Close-up of the prepared strips

 

 

Treatment

Once the materials were ready, we placed the maps on a blotter and Bondina, verso facing up. Because the maps were of a large format, we treated each half separately. Once they were dry, we reattached them together.

For both maps we squared and positioned the fragments of the maps carefully, leaving 3mm space gap for the joints, and kept them in place under weights. Wheat starch paste was applied with a noribake to the prepared strips previously placed on plastic strip. This made the handling easier and the application on the joint to be repaired. Once the strip was on the map, we applied some pressure with a shirobake over the plastic strip. The plastic strip was then removed, leaving the prepared strip on the map and we applied more pressure with a nadebake and with a Teflon spatula. It was left to dry with a Bondina, blotter and weights on top, (video 2 and picture 10).

Video 2: Pasting the prepared strips on the tears of IOR/X/10066

Finally, strips of Japanese tissue (7.3g/m2 with kozo fibers) were applied on the joints of the recto of the maps to reinforce the hinge on both sides of the map, (picture 11).

A close-up of the verso, which is an off-white colour and shows strips of a slightly whiter Aerocotton along the joints.
Picture 10: Detail of the Aerocotton lined with Japanese tissue applied into the verso of IOR/X/10065 to mend the tears
A detail of the map with the strips barely visible along the joints.
Picture 11: Detail of the Japanese strips applied on the same map

 

Results

This treatment was successful on both maps. They can now be handled and stored safely. See video 3 and after treatment pictures 12 and 13.

Video 3: Handling both maps after treatment

 

Overall image of the recto of the IOR/X/10065 map after treatment. The 7.3 gsm Japanese tissue strips are slightly visible on the joints of the map.
Picture 12: IOR/X/10065 recto after treatment

 

Overall image of the IOR/X/10065 verso after treatment. The prepared strips, pasted and dried on the verso of the map, are slightly visible on the joints.
Picture 13: IOR/X/10065 verso after treatment

 

Upper part of the recto of the IOR/X/10066 after treatment. The 7.3 gsm Japanese tissue strips are slightly visible on the joints of the map.
Picture 14: Upper part of IOR/X/10066 recto after treatment

 

Upper part of the verso of the IOR/X/10066 map after treatment. The prepared strips, pasted and dried on the verso of the map, are slightly visible on the joints of the map.
Picture 15: Upper part of IOR/X/10066 verso after treatment

 

Tania Estrada Valadez and Camille Dekeyser

03 May 2023

Whales, horses and zebras—oh my! Conservation work for the Animals: Art, Science and Sound exhibition

In preparation for the Animals: Art, Science and Sound exhibition, Conservation assessed the suitability for display of over 150 BL collection items, of which just over 120 items actually made it into the exhibition. Seventy of these items came into the conservation studio for treatment prior to being displayed. The kind of treatment for each item varied greatly. Some volumes needed intensive treatments because the covers had become completely detached, and others just needed some minor care, such as tidying board edges that had become split and frayed. Some of the paper items needed tear repairs or flattening because they had been stored rolled or folded and many of them needed window mounting so they could be framed or displayed vertically.

The conservation work for all the items was shared between many conservators in the studio. The work started in January, giving team members enough time to complete their treatments prior to the install of the exhibition in March. Conservation play an integral part of the exhibition process and without the support we provide, many of these wonderful items would not make it into the show.

Below, three conservators discuss a few items that came through the studio for treatment ahead of the exhibition.

Amy

I worked on several volumes for Animals.  My favourite was Or.917, which contains very detailed paintings of whales. . My attention was immediately caught by two in particular – as well as being beautifully painted they both have rather evocative facial expressions!

A painting of a killer whale on a cream background. It is shown from the side, with its tail in the air and its flippers held out on either side of its body. The whale is mostly black except for its belly, which is grey and white. The whale’s eye is half-shut and it looks sleepy. Its ear is shown as a little white circle behind the eye. Its mouth is open, showing its pink gums and sharp white teeth. There are eight labels in Chinese characters which are joined to the whale’s dorsal fin, eye, tongue, ear, blowhole, and belly with red lines.
Painting of a killer whale
A painting of a mottled grey whale on a cream background. The whale’s skin has been given a textured appearance on its back and side by manipulating the paint with a circular sponge or fingertip. It is shown from the side and holds its flippers out on either side of its body. There are areas of small white dots on the whale’s back, belly, tail, jaws, and on one of its flippers. This gives the impression that the whale is covered with barnacles. It also has small white whiskers on its chin. The whale’s eye is half shut and the curve of its mouth is like an upside-down smile. There are ten labels in Chinese characters which are joined to the whale’s chin, back and belly with red lines. Below the whale’s head is a picture of a piece of baleen – it is a small white rectangle with long hair-like strands extending from one of the long sides. It is also labelled in Chinese characters with a red line.
Painting of a whale with barnacles

The most badly-damaged book was an early nineteenth-century volume entitled Fishes of the Ganges (Mss Eur E72). When the book came to the conservation studio the paintings themselves were in good condition, but 200 years of usage had taken their toll on the volume’s binding. The green leather of the spine was badly abraded and several pieces of it were missing. This posed a structural risk to the book, as it made it more likely that the boards would become detached at some point in the future. The red-brown paper which covered both boards was also not in a good state, with the pigment faded and rubbed away and pieces missing at the corners and edges of the boards.

A hardcover book against a grey background, photographed showing the front cover.  The book is covered in reddish-brown paper with a blue marbled pattern and a blue-green leather spine. Some areas of the paper are cream-coloured where the reddish-brown pigment has been rubbed away. The leather has split vertically down the edge of the cover and also has cream covered areas where the top layer has rubbed or peeled off. The paper and leather are missing at the corners of the cover, exposing the brown board underneath.
Mss Eur E72 before treatment

As conservators our aim is always to retain as much original material as possible when carrying out treatment. My repairs to the marbled paper were very minimal. Using acrylic paints I toned a piece of Japanese handmade paper to a similar colour to that of the original, which I then used to fill in the gaps on the corners and edges of the boards. The damaged leather required a more interventive approach. After careful consideration I concluded that it was not possible to both keep the original leather and reinforce the binding structure. I therefore replaced the old leather with new green goatskin, but retained the old pieces so that readers can still access these remnants of the original binding. An additional result of this treatment will be that when Fishes of the Ganges returns from exhibition it will be robust enough to be consulted by readers and researchers without (hopefully) sustaining further damage.

The same hardcover book against a grey background after conservation treatment, photographed showing the front cover.  The old damaged leather is gone and the spine is covered in new, dark green leather. The exposed corner areas on the right-hand side of the cover have been covered with reddish-brown paper, a slightly lighter shade than the original.  The paper still has cream-coloured areas where the reddish-brown pigment has been rubbed away.
Mss Eur E72 after treatment

 

Veronica

The animal protagonist of a volume I treated for this exhibition is the horse. ‘The Anatomy of the Horse’, 1766, a printed book by the British painter George Stubbs, includes exquisite etchings engraved by Stubbs itself, which are anatomically accurate and elegant. The binding is a purple quarter leather binding with purple covering cloth on the sides of the boards and parchment reinforcement on the corners beneath the covering material. The leather spine is gold tooled with the author’s name, title and place and date of publication. The numerous plates in the text block were printed on thick laid paper.

The right page of the intended display opening, showing an incredibly detailed black and white full body anatomical drawing of a horse, with its head facing right and tail facing left. There are clear plate lines an inch or two away from each edge of the page, showing this image was printed from a plate. Small text at the top right corner, within these plate lines, reads, “Tab IV”. The top and fore-edge of the right board are visible, showing a dark maroon covering material, with gold tooling forming a thin line close to and parallel with the board edges. The covering material has detached from both board corners and the boards are delaminating, this damage is more pronounced in the top corner.
Tab IV. Exhibition opening page.

The binding was in poor state of condition, with both boards detached, delaminated and with missing areas, and the cloth and parchment covering materials on the corners considerably abraded. The leather was split along the spine edges and was heavily worn and coming unattached on the spine, with the grain layer flaking heavily, and some missing areas at head and tail on the endcaps, along the bands and along the edges. The gold tooling on the spine was partially missing.

The left board of a maroon cloth bound volume is partially visible; the fore-edge side of the board is out of frame, the spine edge in frame. The edges of the board are a slightly lighter colour, the covering material visibly detaching from the tail edge. The spine piece is heavily degraded, with the spine leather completely detached from the spine in places and the leather join split almost the length of the spine.
Left leather join split.
A maroon cloth bound volume lies flat on top a grey surface, showing the spine and the left board. The spine is visible in full, lying horizontally across the frame. The spine leather is heavily degraded, only small sections of dark leather can be seen, as the majority of the leather visible is a light brown and appears fluffy in texture. There are six separate spine sections, split by five raised bands, at least two of these raised bands have been lost completely, a further two are heavily abraded and damages and the final band is not visible due to the spine pieces on either side being so detached that they cover this area. The Spine pieces at the head and tail end have also come detached. There are two labels adhered to the head edge of the spine. There is gold lettering and tooling in every section on the spine. The other sections show design/emblems.
Highly degraded leather spine.

The conservation treatment started with the consolidation of the board corners, by reconstructing the missing areas with layers of Japanese paper adhered with a reversible adhesive. Next, we stabilised the parchment board corners with Japanese paper. The boards protected the text block again!

Once the treatment of the boards was completed, we proceeded with the removal of the old spine lining which was acidic and inflexible and caused the volume to not open well. For the lining removal, we used a poultice, locally applied to the spine to soften the lining materials and adhesives used in the past. The new spine lining, made of Japanese paper and aero-cotton, was strong and flexible and has the function to suitably support the text block spine during opening.

For the treatment of the highly degraded leather spine, together with the exhibition and loans manager and the departmental curator, we carefully evaluated the most suitable option.  Considering that the leather spine’s original state was already been lost and had no historic significance, we decided to apply a new leather spine on the book, gold tooled in the design of the original, and to keep the original pieces, consolidated, in a polyester pocket, secured into the box. With this solution, the volume could be safely displayed and handled, while as much as possible of its physical integrity was retained, with the original spine pieces available for research.

The leather reback on the spine was carried out with a goatskin leather that matched the colour and grain of the original one and was worked to the desired thickness. The treated book was finally housed in a phase box.

A maroon cloth bound volume lies flat on a grey surface. The entire left board is visible and the spine piece is partially visible. The covering material does not cover either of the board corners, which are white rather than maroon, though the corners are not bent or delaminating. Gold tooling of a thin gold line is visible along all edges of the left board, other than the board corners. A reddish brown leather covers the spine, with five raise bands visible along the spine. There is a slightly larger gap between the bottom band and the tail edge than there is between the top band and the head edge, with equal spacing between the raised bands.
Left board after treatment.

 

Old spine leather that has been removed from a volume, in six separate pieces, in a long thin melinex pocket. Each piece of leather is heavily degraded, some of the leather a darker brown but the majority a light brown. All sections of the spine have lost their original shape due to loss of leather. Gold letter is still visible on the second piece from the top, reading, “STUBBS ANATOMY OF THE HORSE”. Gold tooling is visible on all other sections. The top and bottom section show the emblem of a crown, whilst the other three sections show the same decorative emblem. The top section has two labels: a blue circular label reading, “460 f13” and a white rectangular label reading, “74/”.
The original consolidated leather spine is attached by means of Western handmade paper strips to a Melinex pocket sealed on all sides and to the box where the volume is housed.
A reddish brown leather spine piece lies on a grey surface. This spine contains five raised bands, which create six separate spine sections, each complete with gold tooling. A double gold line is at the top and bottom of each section, the top section also shows the emblem of a crown and a white rectangular label reading, “…”. The second to the top section contains gold lettering reading, “STUBBS ANATOMY OF THE HORSE”. The bottom section also depicts an emblem of a crown, and lettering reading, “74/460.f.13”. The other sections depict the same decorative emblem.
New leather spine with gold tooling.

Storm

Historia Aethiopica is a beautiful parchment bound volume I helped treat for display in the Animals: Art, Science and Sound exhibition. This volume included three foldout folios that protruded from the text block even when folded in resulting in heavy creases and weakened paper that had led to tears and areas of loss. I surfaced cleaned the display pages and other pages I treated which displayed surface dirt, to prevent moisture from any materials used in the treatment from causing the dirt to further bond to the surface and to improve the overall appearance of the object.

Volume lies open on conservator’s bench, surrounded by different size and shaped weights, clamps and other tools. The left board, together with the majority of the Textblock, is resting on a large triangular plastezote book rest. The right page is an oversized fold-out currently folded in, so the images are not shown in full, a tree is visible as well as the long tail of an animal. The right board and remainder of the Textblock are lying flat on the bench on top a layer of blotter and bondina. The top page on this side is an oversized folio that is folded out; the picture shows the verso but a large Zebra visibly fills the page. This folio is resting on a piece of mount board and bondina with three thick boards underneath right side so the page lies flat. Multiple thin Japanese strips are visible, these are tear repairs drying before the excess is trimmed. Two weights sit on top of a piece of mount board and bondina in the top right corner as an infill repair to the corner is drying under weights.
Verso of opening page during tear repair treatment

I repaired all tears and areas of loss on the display page, and other fold out pages, using toned Japanese tissue so the repairs were subtle and did not draw attention, and wheat starch adhesive, a reversible water-soluble adhesive.

The right page of the intended opening, a large fold-out folio depicting a black and white print of a large Zebra standing on a grassy area with two small trees on his left side and two larger trees on his right. There are clear plate lines showing this image was printing using a plate. Text above the zebra reads, “ZECORA QUADRUPES PULCHERRIMA / Lusitanis Buroodo Matto. Priscis / Oi Oaypr O., Asimus syloestris”, text in the top left corner reads, “Pag. 150. N.LXXIX”. All this text is within the plate lines. The page is noticeably dirty, has two small areas of loss along the right edge, one visible tear at the bottom edge in the centre and is noticeably dirty.
The display page pre-treatment
The same page depicted the black and white print of the Zebra is shown. However here it is noticeably cleaner, some of the heavier creases have been reduced, and the areas of loss and tears have been repaired.
The display page post-treatment

I used a heated spatula, with a barrier layer to protect the paper, to reduce some of the heavier creases and to flatten the corners as they were heavily curled. I also used the heated spatula in combination with some wheat starch adhesive to strengthen the edges of the page as they were extremely thin and weak, therefore were at a high risk of further deterioration.

A volume sits on a white surface, only the bottom right corner of the text block is in frame. Text is visible on the top page written in black ink and in Italian, the paper is slightly yellowed at the edges. A heated spatula is being applied to the bottom corner of this page, with a square of blotter beneath the page and a layer of bondina between the spatula and the page
Using a heated spatula to flatten a page’s corner

There was also damage to the binding, a tear at the top edge between the left board and the spine, which would likely have deteriorated further during exhibition, as it would be displayed open causing more stress to this area. I repaired this by inserting a piece of unbleached shirlan cotton adhered with a mixture of EVA and wheat starch adhesive to hold the board and spine together to reduce the risk of it tearing further whilst on display or during future handling.

Parchment bound volume lies on a layer of blotter covered with bondina. Only the top left corner of a the left board and top section of the spine is visible. There is black lettering on the spine, though only part of each word is visible: ‘..OLFI/ ..ariusin /…ICAM”. A piece of acid-free tissue is protruding from underneath the left board. The left board is covered in small scratches and there is a small split at the top edge between the left board and the spine piece. A small piece of white fabric is protruding from this split, having been inserted into the left board side and adhered in place.
The binding repair during treatment
The top left corner of a parchment bound volume is visible, showing the top left corner of the left board and the top section of the spine. The left board is covered in scratches and a small split is visible between the left board and the spine at the top edge, with the left board side of the split overlapping the spine piece.
Damage to binding
The top left corner of a parchment bound volume is visible, showing the top left corner fo the left board and the top section of the spine. The left board is covered in scratches. There is a small split visible but the parchment on either side of the split are almost touching with a small visible white gap between.
Binding repair

Both the head-edge endband and the tail-edge endband had also become almost completely detached from the text block, thus needed to be repaired. As I was unfamiliar with this type of treatment I closely observed as my mentor, Veronica Zoppi, undertook the treatment to the head-endband. This was incredibly educational as I was able to take photos and short videos of each treatment step whilst asking questions, which allowed me to make detailed notes complete with diagrams for future use and to treat the tail-edge endband.

First, I cleaned the endband and spine edge of the textblock using Konjac and Xantham gel, to improve the appearance of the endband but also so the repair materials would adhere properly.

A hollow-back parchment bound volume stands upright on a conservation bench on top of a piece of blotting paper. The volume is opened at roughly the centre, fairly wide, exposing the hollow. A green and white endband is visibly detached from the text block, there is a thin strip of the text block closest to the spine much lighter in colour than the rest, where the endband would have once covered. The endband is lying flat across the hollow, it is attached the volume on the right side but the left side of the endband is detached and the central core is visible. There is gel covering the endband.
Endband with gel on during cleaning

The endband was then fixed in the right position using a strip of Japanese tissue adhered to the bottom edge of the endband and to the spine of the Textblock, this was then left to dry shut.

A parchment bound volume lies closed on a piece of blotter and bondina. Only the spine side of the head edge is visible. A green and cream sewn endband follows the curvature of the spine. There is a small piece of bondina and a small piece of melinex protruding from between the text block and the spine.
Japanese tissue holding endband in position drying

To reattach the endband, I sewed through the text block, around the endband core, passing again through the centre of some sections in the text block, marked by paper markers. Usually when re-attaching endbands a conservator would have access to the spine of the text-block, as the spine piece would have been partially or completely detached. As this was not the case, to allow access to the spine, the volume was held open with weights, and then a curved needle was used to reattach the endband using linen threads that closely matched the original endband colours.

A thick volume is held standing on a conservation bench, on top of a layer of blotter and bondina. Only the head edge of the volume is visible, with the fore-edge out of frame but the endband and spine edge visible. Six paper markers spaced approximately evenly throughout the text block, protrude slightly from the head edge.
Section markers
The head-edge of a parchment bound volume is partially visible, with the fore-edge side and the majority of the head-edge of the volume out of frame. A green and cream endband is visible with a clear gap between this endband and the text block and another gap between the endband and the spine.
The endband pre-treatment
The head-edge of a parchment bound volume is partially visible, with the fore-edge side and the majority of the head-edge of the volume out of frame. A green and cream endband is visible, the endband touches the text block at the very left edge, but a small gap is visible between the endband and the text block, this gap widens from the centre to the right side. There are three very thin threads visible in this gap; this is the repair stitching holding the endband in place.
The endband post-treatment

Conclusion

We hope you’ve enjoyed this glimpse into preparing items for display. All items are now on view in the exhibition. Book your tickets here.

12 April 2023

Preserving Bach’s manuscripts

Two Johann Sebastian Bach manuscripts in the British Library’s music collections - the autograph manuscript of the second book of the Well-Tempered Clavier (BWV 870-893) and of the cantata ‘Wo soll ich fliehen hin?’ (BW 5), recently came into the conservation studio. Treatment was undertaken with generous support from the Leche Trust.

This blog post focuses on the work undertaken on the Well-Tempered Clavier manuscript, which we are pleased to say is now complete.

A musical manuscript showing Bach’s Prelude in C Major. The musical notes have been busily squeezed onto one bifolio. The musical scores have been drawn by hand in a thick dark brown ink on brown paper, which has evidence of being folded previously in half. The bifolio has been mounted in a brown inlay paper which has discoloured over time causing it to darken in colour. The title of the piece is written above the musical scores and it has been signed by J. S. Bach alongside this, his writing is expressive.
Prelude in C Major (before treatment)
This image shows a close up of a brown musical note where the centre of the note is missing, it appears to have dropped out of the page, due to the corrosive and thickly applied ink.
Effects of Iron Gall ink corrosion; Iron gall ink has been used since the middle ages and is found on many of our most treasured manuscripts, including the Lindisfarne Gospels, Beowulf and Magna Carta. The main ingredients of iron gall ink include iron sulphate, tannins from oak galls and water.

 

The Well-Tempered Clavier, Book II

Bach’s Well-Tempered Clavier (named after a system of tuning – ‘well temperament’) is one of those musical works that seems to justify the grand claims made about it. On the face of it, it’s a simple series of preludes and fugues in every key, major and minor: 24 in all, with two sets of these (giving the series its nickname ‘the 48’)’. But it’s also a jaw-dropping feat of compositional virtuosity, with Bach using his immense contrapuntal skills to weave together separate musical lines that fit together logically (but never too predictably) and yet also produce inspired music at the same time.

The British Library’s manuscript of the second book of the Well-Tempered Clavier (Add MS 35021 and Add MS 38068) is really a set of individual manuscripts for 21 of the preludes and fugues in the second book (those in C-sharp minor, D major and F minor are unfortunately not preserved here and must have been separated from the others at an earlier date). These were composed between 1739 and 1742.

Each prelude and fugue were mostly written out to (very satisfyingly) fit on a single side of an open folded page, avoiding the need to turn the sheet over – even if this at times means a bit of a squeeze. (No amount of squeezing was going to fit the lengthy prelude and fugue in A-flat major onto one side – this carries on over to the next side). Most of the pieces have been written out by Johann Sebastian Bach himself, apart from four and a bit which are known to be in the hand of his second wife, Anna Magdalena (those in C minor, D minor, E major, G major and the beginning of the prelude in F major).

A musical manuscripts showing Bach’s Prelude in C minor, this has been written in the hand of Anna Magdelena Bach, the second wife of J. S. Bach. The musical scores have been drawn by hand in a thick dark brown ink on brown paper, which has evidence of being folded previously in half. The bifolio has been mounted in a brown inlay paper which has discoloured over time causing it to darken in colour. The title of the piece is written at the top of the piece, A. M. Bach’s writing is much neater than J. S. Bach’s.
Prelude in C minor (BWV 871), in the hand of Anna Magdalena Bach (before treatment)


Planning – what were the issues?

Unfortunately, even in optimal storage conditions, chemical and physical processes that pose a risk to manuscripts like these can, over time, still occur. We minimise threats to the collection as much as possible, by controlling factors like temperature and humidity, by using appropriate housing and by limiting access to, and use of, particularly vulnerable materials. However, even with strict environmental monitoring a common problem that is difficult to halt entirely is one of iron gall ink corrosion. Like much music of this period and earlier, these Bach manuscripts are especially at risk from this due to the make-up of the inks that were used – iron sulphate and acidic tannins in particular, which, over time, oxidise and ‘eat away’ at the paper. There’s an interesting blog post on this here:  https://blogs.bl.uk/collectioncare/2021/06/iron-gall-ink-on-paper-saving-the-words-that-eat-themselves.html.

When it came to planning conservation work, there were two main issues to consider. One was the corroding ink, as mentioned above. This is a particular problem where the ink is applied thickly to a small area, as tends to happen when writing expressive music notation. There were various examples of this on the Bach manuscript, ranging from visible holes to less obvious hairline cracks, making it extremely vulnerable.

The other issue was previous methods of preservation in manuscripts past - the manuscript pages had been bound into a single large volume, with each folio mounted into paper windows. This mounting paper had aged poorly, shown in the image below. Over time, its acidic properties have led to it discolouring and becoming brittle – meaning some were no longer secure in the binding. Tension from the acidic border was also causing stress to the centre of each bifolio of the manuscript, increasing the risk of splitting. It was clear that the time had come to give the manuscript a more appropriate long-term home.

This is a photograph of the previous binding that the manuscript was house within, it is a half leather binding with brownish purple goat skin on the spine and corners and deep purple cloth on the boards. There is two lines of gold tooling along the leather edges at the spine and corners. The edges of the boards and spine are worn and the pages inside the binding are protruding from the edges, implying that the sewing has broken down. The book sits on a plain grey background.
Previous binding for Add MS 35021
This shows the inside of the binding, showing Bach’s prelude in C Major (the same manuscript is shown in Image 1), it is sitting inside the binding surrounded by the discoloured and acidic inlay paper which has gone from cream to brown.
Manuscript folios mounted in paper inlays inside (before treatment)



Conservation over time

Something that really made an impression in the course of this project was the changing approach to conservation over the years – understandable given evolving knowledge, the emergence of new technologies and shifting emphasis in professional standards. However, while treatment undertaken decades ago might appear questionable now, we are mindful that it was done with the best intentions given the tools and knowledge available at the time.

A good example is in relation to iron gall ink. There are very few ways to fully halt the corrosive effects of the ink and limiting the damage is often the only approach. However, one treatment that emerged in the mid-1990s involves an aqueous treatment, using a calcium phytate solution to neutralise the acidic iron content in the ink.

In recent years, the British Library has established processes for this treatment, but still it is not something to be undertaken lightly. While extensive testing prior to treatment ensures that both the structure of the paper and the ink will remain secure, nonetheless the process has the effect of washing the paper. Therefore, this results in the removal of dirt and accretions but also, potentially valuable but less obvious, evidence of historical use.  

The decisions are not easy, as weighed against the potential risk of sometimes losing potential sources of historical evidence, such as staining on the paper, is the risk of the manuscript deteriorating to such an extent that any kind of study becomes impossible.

Decisions

Given the iconic status of this manuscript, many people were involved in the decision-making and the project was a collaboration between curatorial and conservation teams. One objective that was clear was the new housing needed for the folios of the manuscript, which would keep them more secure.

In terms of treatment of the iron gall ink, we decided to take a cautious approach for now, and only apply the calcium phytate treatment to two folios, which suffered from different and more pressing issues from the others. These (which contained the A-flat major prelude and fugue, ff. 13 and 14), had been removed from the bound volume more than a century ago. At different points since then they had received conservation work of differing levels of invasiveness, including a coating of transparent heat set tissue applied to one side of the fugue and repairs along the fold of that page too. The aim in focusing a higher level of treatment on these particular folios was to stabilise the corrosive properties of the ink on one of the most problematic examples among the Well-Tempered Clavier manuscripts, and also to reduce some of the ill effects of previous treatments. This work would also make it possible to safely rehouse these folios in the same way as the others, removing them from their unsuitable temporary storage.

This shows Bach’s Prelude in A-flat major which is obscured slightly, appearing fainter to the other images of the musical scores – this is due to a thin layer of heat-set tissue which was previously applied to the manuscript which is unsympathetically covering the music. At the edge of the page a darker brown boarder can be seen, this is the acidic inlay paper which was then removed by conservation.
Prelude in A-flat major, f. 13v, showing coating of heat set tissue.

 

Conservation work begins

All our manuscripts are special and unique of course, and receive due care and attention to ensure their long-term preservation. Often there are particular manuscripts that are so iconic that you find yourself to be quite awestruck in their presence, this was certainly the case here and it was a wonderful moment when the volume containing the manuscripts was unpacked in the conservation studio. We took a moment to listen to the pieces as we looked at the score, we felt humbled in that moment as we contemplated the music that had inspired so many, as the notes on the page seemed to dance before us.

After thorough documentation and testing, treatment began by disbinding the volume and removing the folios from the acidic inlay paper; this was done mechanically using a poultice of sieved gelatine mousse. Whilst removing the old acidic paper mounts we uncovered the edge of the text previously covered by the inlay.

Bach’s Prelude in A-flat major during aqueous treatment. The image shows a close up of the corner of the manuscript under water, a reflection on the water’s surface can be seen. Held in place by the conservators hand, at the top of the image the handle of a metal spatula can be seen gliding under the edge of the cream manuscript, separating it from the brown acidic boarder.
Removing remnants of acidic paper mounts during the calcium phytate bath

Aqueous treatment of the two folios

The treatment of folios 13 and 14 was achieved in three stages: first the documents were washed then treated with calcium phytate and then calcium bicarbonate. This helped stabilise the corrosive properties of the ink and remedy some of the ill effects of the previous treatment. 

Prior to immersion, multispectral images of these folios were taken by our imaging scientist, ensuring we have a clear record of the manuscript prior to treatment. Multispectral imaging captures image data within determined wavelength ranges across the electromagnetic spectrum. It can be used to examine discolourations and staining, by comparing the "spectral fingerprint" of an accretion to a known chemical substance. It can also reveal things that are only visible on different parts of the spectrum and allow us to capture the true colours of the image to accurately assess any ink changes after treatment.

This shows a multispectral image of the manuscript, the image appears black and white. The media appears dark and various stains and accretions are visible and appear lighter.
One of the series of multispectral images

The existing condition of these particular folia made them a priority to treat in this way, but the experience of doing so will allow us to weigh in the balance the benefits or not of undertaking similar treatment on other folios in the future, should the degradation of the corrosive ink progress. For now, fragile inks on the other folios of the manuscript have been supported with a very fine toned Japanese tissue and gelatine using a low moisture technique. This was carried out over a light box to ensure any weakened areas of iron gall ink were spotted.

After Treatment

All the folios have now been housed individually in a more sympathetic, double sided mount. This rigid mount allows each page to be correctly supported and viewed in full and is suitable for both storage and exhibition display, minimising the need for handling or further work. The mounted folios were then stored in several bespoke acid-free phase boxes to offer additional protection on the shelf.

This image is of all the folios, stacked in a pile in their new rectangle cream mounts and cream inlays which have been cut to the exact size of the folios and adhered with a lightweight Japanese tissue along the edges. The mount is double walled, giving the manuscript a layer of rigid protection, and also allowing them to be displayed cleanly within their mounts as the cover/supportive board can pivot on the hinge attaching it to the window mount.
The conserved folios in their new mounts (after treatment)
This shows one of the musical folios inside a cream window mount and cream inlay paper. The inlay paper has been cut to the exact size of the folio, so the uncut edge can now be seen. The window mount has a bevelled window cut which frames the manuscript. The mounted manuscript sits on a plain grey background.
Prelude in G major (BWV , f. 23r, after treatment)

Conclusion

Thank you to the Leche Trust for their generous support which allowed the items to be conserved and ensured that the manuscripts themselves are now better preserved and protected for posterity.

The British Library’s responsibility as custodian of these iconic examples of Bach’s creativity involves finding a balance between protecting the physical manuscripts and finding ways for their appreciation by a wide audience. High-quality digital images are a key tool for providing access, but this conservation treatment will also make it possible for researchers to work with the original material where this is necessary – further enhancing our understanding of Bach’s creative practise. It is also now safer to exhibit these iconic collections beyond the reading room, in our gallery spaces, where you can join us and experience the real thing.

Samantha Hare and Chris Scobie