Collection Care blog

The Collection Care blog is a year old this week! It has been a wonderful 12 months for the blog, due largely to you, our loyal readers. Since fluid, food and flames are generally considered our nemeses, we'll hold off on the champagne and birthday cake. Instead, to celebrate, we have compiled a list of the top ten most popular posts. Boy, do we know how to party!

10. A-a-a-choo! Collection Care's Dust Busters: In this post we shared the work of our dust busting team who monitor dust in order to protect our collections. We took a look at what exactly dust is, and how to balance the benefits and risk of dust minimisation programs. Who you gonna call? Collection Care! 

9. Goldfinisher: He's the man, the man with the Midas Touch: Doug Mitchell is our book conservator and gold finisher extraordinaire. Doug demonstrated the blind tooling technique and showed us the variety of tools involved in the process.

8. Sea Snails & Purple Parchment: Did you know that the colour purple found in many of our manuscripts comes from sea snails? The snails are essentially "milked" to extract a gland secretion in a very labour intensive process. 

7. A Guide to BL book stamps: You've seen them on our collections and online, but what do they mean? Library stamps are generally divided into four types according to when they were in use, ranging from 1753 to the present day.

6. Digitisation as a preservation tool; some considerations: This post by Qatar Project conservator Flavio Marzo confronted the growing public expectation for online access. Marzo challenged the conservation community to use mass digitisation as an opportunity for the long term preservation of historical items and their features.

5. The Bookie Monster: attack of the creepy crawlies!: Here we delved into the underworld of pesky pests who seek to eat their way through our collections. We identified some of the primary culprits and showed examples of damage to look out for.

4. Cleaning and rehanging the Kitaj tapestry: What happens when creepy crawlies do successfully attack? This year we had to don our hard hats to remove the enormous R.B. Kitaj Tapestry If not, not from the St Pancras Entrance Hall for conservation cleaning. The tapestry was hoovered and frozen to remove all pests and surface dust before rehanging in the hall. It was a major operation and a complete success. We even made a time-lapse video!

3. Fail to prepare for digitisation, prepare to fail at digitising!: Digitisation is much more than just taking a picture. With mass digitisation projects being announced every month, we shared what we've learned when it comes to preparation. We listed five main outcomes of pre-digitisation checks, which highlighted the potential risks in each case.

2. Books depicted in art: Being surrounded by books everyday is all part of the day job for us here in Collection Care. As you can imagine, seeing books in paintings can be quite thrilling. In this lavishly illustrated post we saw that some historical paintings contain a wealth of information about bindings that were not well-documented in the trade.

1. Under the Microscope with the Lindisfarne Gospels: Finally, in our most popular post, we shared microscopy images of the Lindisfarne Gospels collected by our team during a condition assessment. At up to 200 times magnification the medieval artistry and attention to detail blew us all away.

Many thanks to all our readers from the Collection Care team. As ever, we are truly grateful for your following and are always keen to hear from you. Do let us know if there are any topics you'd like to read about, and don't forget you can subscribe to the blog at the top of this page, and follow us on Twitter: @BL_CollCare

Christina Duffy (@DuffyChristina)

This week we celebrate the 379th birthday of Robert Hooke, a Fellow of the Royal Society and key figure of early modern natural history and natural philosophy, born on 28 July 1635. Many of Hooke's innovations paved the way for a more rigorous scientific analysis of materials, for which we in Collection Care are very grateful. To mark the occasion we are thrilled to host a guest post from Puck Fletcher who has just completed a doctorate on space, spatiality, and epistemology in Hooke, Boyle, Newton, and Milton at the University of Sussex:

Hooke’s most famous work is the Micrographia: or Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses with Observations and Inquiries thereupon, published in 1665 by the Royal Society. It is a descriptive work detailing sixty observations of specimens at magnification, starting with the point of a needle, ranging through silk, glass drops, hair, and various plants, seeds, and tiny insects, all viewed through a microscope. It closes with observations of the fixed stars and the moon as seen through a telescope. 

Two cross sections of cork and a ‘sensible’ plant. In his description of cork, Hooke coined the term ‘cell’ for biological contexts. Image source.

The project was a collaborative one started by Christopher Wren who, in 1661, so impressed Charles II with his drawings of magnified fleas and lice (possibly the ones on which the corresponding Micrographia engravings were based), that the King requested more. Wren persuaded Hooke to undertake the bulk of this work and over the next few years, Hooke amassed his collection of observations, regularly bringing new drawings to the meetings of the Royal Society for approval by the other members.  

Among the drawings and observations in Micrographia is this famous and extraordinarily detailed large-scale illustration of a flea. BL Shelfmark: 435.e.19, XXXIV. Image copyright The British Library Board. Read more.

The impressive folio volume contains thirty-eight highly detailed engravings, which turned the book into an instant bestseller and secured its reputation as the most beautiful and lavish work of early European microscopy. The sense of magnified scale is staggering. A head or body louse, for example, is just a few millimetres long, but the engraved image is 52 cm long, roughly two hundred times actual size, a level of exaggeration that is emphasized by the fact that, large as the volume is, the reader must still unfold the oversized plate to view it.

Engraved image of a head or body louse, roughly two hundred times actual size.

 Image source.

For his readers, Hooke’s illustrations brought a whole new world into view. Hooke captures this excitement in his preface, describing how, by means of instruments like the microscope, ‘the Earth it self, which lyes so neer us, under our feet, shews quite a new thing to us, and in every little particle of its matter; we now behold almost as great a variety of Creatures, as we were able before to reckon up in the whole Universe it self.’ Pepys was famously so enamoured of the book that the day after he brought home his copy, he stayed up until two in the morning reading it, describing Micrographia in his diary as, ‘the most ingenious book that I ever read in my life’. 

When looking at the large-scale, clear engravings in Micrographia, it is easy to imagine that this was the view Hooke had in his lens and that his task was simply that of looking and then recording what he saw. However, the practice was much more difficult and required considerable skill and experience – when Pepys looked through his microscope, he was disappointed to find that at first he couldn’t see anything at all! The lens making technology of the time meant that impediments to clear vision such as chromatic aberration or artefacts in the glass were not uncommon, and the view through a microscope was often blurred, distorted, and dark. It was difficult to make out true colours or to tell whether a shadow was a depression or protuberance, and the field of vision was quite small.¹

Part of Hooke’s contribution in Micrographia was his skill as an instrument maker and technician. Although, as he reports, he had difficulties in seeing through his microscope, Hooke made his own adaptations to the commercially manufactured instrument, in particular devising an improved light source, which he called his ‘scotoscope’.  

The microscope, featuring an improved light source.

 Image source.

Hooke also worked diligently and looked very carefully, making multiple observations from multiple angles, of multiple specimens, created with various preparation techniques, to gather enough visual information to be able to produce a single image of what the whole object looked like, as near as he could make out. For Hooke, the act of looking through the microscope and recording what he saw was an interpretive one.

Hooke’s observations have been praised by modern scientists for their accuracy, and Howard Gest even credits him with the first accurate description and depiction of a microorganism, the microfungus Mucor, described by Hooke as ‘blue mould’.² 

The microfungus Mucor (‘blue mould’).

 Image source.

In his preface to Micrographia, Hooke heralds ‘artificial Instruments’ such as the microscope and telescope, and the methods of the new science based on observation and the careful and rational scrutiny of results, as at least partial correctives for the failings of fallen man and his limited sensory faculties. He also looks forward to the technology of the future, which he believes will enable man to see even more clearly.

‘’Tis not unlikely, but that there may be yet invented several other helps for the eye, at much exceeding those already found, as those do the bare eye, such as by which we may perhaps be able to discover living Creatures in the Moon, or other Planets, the figures of the compounding Particles of matter, and the particular Schematisms and Textures of Bodies.’

Puck Fletcher

¹Brian Ford’s wonderful book, Images of Science: A History of Scientific Illustration (The British Library, 1992), pp. 182–83, contains a photograph of the partial and distorted view through the sort of lens used by Hooke.  

²Gest, Howard, ‘The Remarkable Vision of Robert Hooke (1635–1703): First Observer of the Microbial World, Perspectives in Biology and Medicine, 48.2 (2005), 266–72 (p. 267).

Conservation work never ends; we had just finished working on the Comics Unmasked exhibition when the First World War material arrived in the studio. The next exhibition: Enduring War: Grief, Grit and Humour in the Folio Society Gallery is a very topical one. The year 2014 marks the First World War Centenary and the start of commemorative events worldwide. In Britain a number of interesting documentaries, discussions, drama, etc., aiming to explain the events leading to the outbreak of the war have already been aired on television, radio and other media. The First World War Centenary commemorations have not by-passed the British Library.

The exhibition: Enduring War: Grief, Grit and Humour opening on 19 June 2014, is part of the Library’s contributions to these events. The exhibition will showcase nearly 80 items from our collections looking at the human aspect of the war, and how ordinary people coped with the momentous events of the war. The space for the exhibition in the Folio Society Gallery is smaller than for our main exhibitions, but it will host some large and well known recruitment posters and leaflets, together with smaller, less known and more personal items including letters, postcards, photographs, poems, prayers, songs and even knitting instructions!

Out of the 30 items prepared for the exhibition by the conservation department the majority needed standard hinging and mounting, but some also had to be flattened and repaired.

Trimming a corner repair

Finished repair

 Pictures 1 and 2: Trimming a corner repair and the finished repair showing the top right hand corner of ‘How the World Is at War’ certificate.

The ‘How the World Is at War’ certificate is one of many the Overseas Club produced for schoolchildren who raised money for soldiers and sailors serving in the war. The one above was issued to Elsie Donald in 1916.

Below are two examples of World War One recruiting posters: ‘These Women Are Doing Their Bit Learn to Make Munitions’ and ‘Lads You’re Wanted: Go And Help’. Both posters are displayed on the wall and needed to be mounted flush (hence flush mounted) onto 100% cotton Museum Board for support.

Adhering hinges

Attaching hinges

 Pictures 3 and 4: Adhering Japanese paper hinges to the back of a poster and then attaching them to the back of the board.

War time poster

 Picture 5: The poster ‘These Women Are Doing Their Bit Learn to Make Munitions’ mounted and ready for the exhibition.

The poster ‘These Women Are Doing Their Bit Learn to Make Munitions’ designed by Septimus Edwin Scott and measuring 760 mm x 510 mm is one of the larger posters in the exhibition. The black, yellow and purple lithographic print was issued by the Ministry of Munitions in 1916-17 and was aimed at recruiting women for the war effort. The campaign must have been very effective - by the end of the war almost one million women were employed in the war industry supplying munitions and weapons to the Front.

The ‘Lads You’re Wanted: Go and Help’ poster below is smaller, but no less powerful in its message. It measures 760 x 150 mm and is quite long. It was folded in half in storage and therefore required flattening prior to mounting.

Flush mounting

 Picture 6: Attaching a poster to a board (flush mounting).

War time poster

 Picture 7: Finished poster ‘Lads You’re Wanted: Go and Help’.

The poster showing soldiers in silhouette will be displayed in the first section of the exhibition explaining how and why people joined the army. The black-and-yellow lithograph was published by the Parliamentary Recruiting Committee in 1915. The Committee’s sole purpose was to assist the War Office in orderly recruitment, and the poster campaign was one way of doing so. The posters were published in great numbers by different printing companies, often with slight variations in design, so all had to be passed as fit for use by the Committee. The poster above is from the British Library’s collection and was printed by David Allen and Sons in Harrow.

The exhibition is only one aspect of the ongoing commemorative events. In the run up to the centenary of the First World War the Library has been involved for three years in a major Europeana 1914-1918 Project digitising hundreds of documents including personal papers, trench journals, photographs, letters - as well as newspapers, maps, posters, etc., all relating to the 1914-18 war. Over 250,000 pages of collection items have been digitsed providing a wealth of the material ready to be explored, interpreted and narrated. A selection of the newly digitised material is available free to researchers, historians and students and is introduced through our new learning website, World War One.

The exhibition ‘Enduring War: Grief, Grit and Humour’ aims not only to showcase the original objects from our collection but will also provide a link to the work done on the Europeana project through an audiovisual art installation.

Iwona Jurkiewicz

This rather ancient looking Qur’an is deceptively young. In fact, it is thought to date back to the early 18th to late 19th century. The style is typical of African manuscripts originating south of the Sahara, and was presented to Lt. Heygate of the British Army, in Nigeria in 1916.

Front

Front Open

 Above: Manuscript in its wrapper. Below: Manuscript sandwiched between its boards with the wrapper open

It has a number of components; starting from the inside, there is an unbound textblock with thick tanned, haired goatskin boards on top and bottom. This in encased in a goatskin wrapper, which then fits into a goatskin satchel. This multi-faceted construction is similar to other 19th-century Qur’ans from West Africa, south of the Sahara.

Satchel

 Satchel lying on inert grey foam, with acid-free tissue padding to retain shape

First page

 Left: Manuscript open at first page with the letter detailing its origin inserted

As exciting as it is to have this fascinating object in the studio, it is responsible for some real headaches as a result of one particular element of its composition. Before an object comes to the studio to be worked on, a conservator will often carry out an assessment of its condition and write a treatment proposal, estimating the time and materials likely to be used. In this case, when my colleagues carried out the assessment, a large proportion of the textblock was ‘blocking’. This simply means pages were sticking together, which meant that most of the book was unreadable.

Strangely, in the period of time between the book arriving in the studio and the point where I took it out of the safe to work on, around a third of the textblock had released itself. This is not something conservators are trained to expect; most things get worse over time, so to see something improve without our intervention was exciting!

The only conclusion we can come to is that the studio’s environment is slightly different to the one the manuscript came from. The difference in the moisture levels in the air is the most likely culprit. 

Pigment detail

 Detail of yellow pigment, orpiment

On closer inspection the ‘sticky element’ was discovered to be yellow dots painted intermittently within the text areas. These were tested by our Conservation Science team, and found to be orpiment (a poisonous, arsenic-based yellow pigment) mixed in a medium of gelatine. It is the gelatine that is fairly hydrophilic, which would have softened in a humid environment and stuck to anything in direct contact with it.

So the obvious solution to this is to change the humidity levels around the volume further, to release all of the sticky dots. If only it were simple! The brown ink you can see in the image is most likely iron gall ink, which has been used as a writing medium since ancient times. Its main characteristic is that once it’s a few years old it turns from purplish-black to brown. Another, less innocuous ageing property, is its potential to ‘burn’ through the paper it sits on. The extent of the damage can depend on the recipe the scribe followed to make the ink; some are more acidic than others. But it can also depend on the level of humidity the ink has encountered in its lifespan. The introduction of medium to high levels of moisture, even in vapour form, can solubilise ions contained in the ink, which can catalyse the oxidative degradation of the cellulose fibres of the paper. This leads to weakened paper and potentially a severely damaged collection item.

Text

 Detail of one of the illustrations amongst the text

So keeping it dry is the best option for the ink, but pulling apart the pages without moisture could lead to skinning off the top layer of fibres, or even tearing paper.

We’re still deciding what to do about this sticky dilemma, but as ever with conservation decisions, we will have to balance our need to enable access by our readers to collection items with the wellbeing of individual items. Never a dull moment!

Jo Blackburn

When items from the Library’s collection (and from other institutions) are exhibited to the public, it is important to ensure that none of the other materials used as part of the display (fabrics, foams, plastics etc.) will cause problems, for example by becoming acidic or releasing reactive gases as they age. As a result we work closely with the British Library’s Exhibitions Department to test the stability and compatibility of any new materials that are under consideration for use.

The ‘Oddy Test’ is an accelerated corrosion test developed by conservation scientist Andrew Oddy at the British Museum in 1973. It is used to predict potential off-gassing from new materials to determine whether they are safe to use with collection items in an enclosed space. The suitability and compatibility of a material coming into close contact with a collection item is predicted by measuring (semi-quantitatively) the extent to which a new material will release harmful volatiles over a long period. If enclosed in a small space, volatile components such as organic acids, solvents, oxidants and sulphur compounds may reach dangerous levels of concentration capable of damaging objects through corrosion of metals or degradation of organic matter.

Fabrics Testing

 Fabrics for testing

Enclosed spaces could include showcases for exhibition, storage crates, contained shelving or individual item storage boxes. It is important to test all of the materials that the collection item will be exposed to in order to ensure the item is not at risk of damage. For example in the case of a new storage box for loan transport we would test a small sample (approximately 1g) of the board, fabric, adhesives and foam which make up the box.

Method

The original Oddy Test has since been developed into the 'three-in-one' method, but the theory is the same. In the original setup samples of the material in question are placed into three separate test tubes. Approximately 1 ml of de-ionised water is placed in a vial inside each of the test tubes to maintain a high relative humidity. In the first test tube a clean metal token of copper (Cu) is suspended over the sample on polyester thread, in the second a token of silver (Ag), and in the third a token of lead (Pb).

The Oddy Test

 Schematic of the 'three-in-one' Oddy Test. Image source

The test is evaluating the extent to which a new material corrodes these metals, and any alloys containing them. Copper, silver and lead are used because they react to a different set of gaseous pollutants, but results are applicable to all material types. Copper detects chloride, oxide and sulphur compounds, silver detects reduced sulphur compounds and carbonyl sulphides and lead detects organic acids, aldehyde, and acidic gases. Three identical test tubes with metal tokens and de-ionised water are setup as a control.

The containers are sealed up with glass stoppers and secured in place with heat-shrink tubing. To mimic the aging conditions they are placed into a heated oven held at 60 °C. This replicates a ‘natural’ ageing process of approximately 5-6 years. When 28 days have passed the containers are removed from the oven and the tokens are examined. The presence of volatiles is indicated by any corrosion or tarnishing of the tokens. The extent of corrosion gives a rough indication of the level of off-gassing. If the tokens show no signs of corrosion then the material is deemed suitable for use with collection items. 

Oddy tests in the oven

 Sealed jars containing Oddy Tests in an aging oven. Image source

Further Oddy Test developments have seen the 'three-in-one' test where all three metal tokens are placed in the same container over the sample, making sure they are not touching each other or the sample. The interpretation of the results is somewhat subjective given that visual cues such as changes in lustre, colour or texture are used to classify the suitability of the test material for use.

Stability of the materials can be further tested with the use of Image Permanence Institute ‘A/D’ strips. These strips measure the short-term release of volatile organic acids. Oddy testing is just one of several tests that a material must pass before it is accepted for use near a collection item. For example infrared spectroscopy allows us to determine the chemical composition of the sample, enabling us to predict its likely behaviour. Surface pH measurements give an indication of the way in which the acidity of the bulk sample changes over time.

By working with conservators and the Exhibitions Department in this way, we help to ensure that the Library’s collection can not only be displayed in the best possible manner, but that it is also preserved for future generations.

Christina Duffy (@DuffyChristina) and Paul Garside

Further reading

The British Museum published the results of material test results (Oddy and pH) carried out on materials at the BM from 1996-2004

Bamberger et al., Studies in Conservation, Vol. 44, No. 2 (1999), pp. 86-90

Robinett and Thickett, Studies in Conservation, Vol. 48, No. 4 (2003), pp. 263-268

In February this year the British Library hosted a course called ‘Recreating the Medieval Palette’ run by pigment expert Cheryl Porter who is also Director of the Montefiascone Project and a freelance conservator. Those of us attending were a small group of conservators and material specialists from the British Library and other institutions hoping to deepen our knowledge of the materials we work with. The course was an interesting mixture of theory and practice, with the morning lectures covering the basic colour groups and the afternoons providing a more hands-on approach giving us the opportunity to prepare and paint out the pigments and inks on a variety of papers and parchment.

Recreating the Medieval Palette

 The group painting out some examples of earth colours made from rocks and minerals – the oldest pigments used by our ancestors

Alongside the history and manufacturing processes of the pigments we learnt about their chemical composition, visual characteristics, behaviour in response to their environment and modes of deterioration. This is essential background knowledge when undertaking a conservation treatment.

The medieval alchemists didn’t worry too much about health and safety in their search for vivid and enduring colours; hence the highly poisonous production methods for concocting pigments such as lead white, red lead, lead tin yellow, verdigris and cinnabar/vermilion. When preparing the pigments for painting, the powder has to be mixed with a binding medium to give viscosity and adhere it to the page. We experimented with different binding agents – egg white and gum arabic – which changed the working characteristics of the pigments when painted out.

Malachite

 Malachite or ‘mountain green’; a naturally mined carbonate of copper

Lead grinding

 Grinding lead white pigment on glass in a figure-of-eight motion

Making some of the lake colours provided an opportunity to see some real alchemy. A lake is a dyestuff made from organic matter which is precipitated onto a colourless mineral base. Plants such as buckthorn, weld and saffron were used to make a variety of colours, and insects such as kermes and cochineal produced shades of red.

Mixing saffron

Painted-out medieval blues

 Left: Experimenting with mixing saffron (yellow) with verdigris (green). Right: Painted-out medieval blues; the brighter colours are mineral-based azurite and ultramarine and the subtler shades, indigo and woad

We also had an opportunity to learn about inks used in manuscripts. This was extremely interesting from a conservator’s point of view as we discovered that inks can often be identified by the way in which they deteriorate over time. The earliest writing implements were reed pen and quill, and the group’s attempts at writing with these proved that both skill and practice were required!

Reed pen

Quill pen

 Left: Practising writing with reed and quill pens. Right: A quill and block of Chinese carbon ink

Colour sample sheet

   Left: One participant's colour sample sheets

 At the end of this highly informative and entertaining week we went away having learnt a lot from Cheryl’s wealth of knowledge and experience, as well as having enjoyed stories of her adventures collecting and researching pigments. Our array of sample sheets will also provide a valuable visual and chemical reference for identifying pigments in the future.

Vicky West

We recently rehung the R.B. Kitaj Tapestry If not, not in the St Pancras Entrance Hall after it was removed for conservation cleaning. You can read about the process and all the gritty details (hoho!) here.

Working with a 6.75 metres high by 6.75 metres wide tapestry is no mean feat and required the help of many people, so we thought we would honour all those involved by immortalising them in a time-lapse video! (Best viewed with Chrome)

The rehanging required the erection of scaffolding several days before and the hoisting of the tapestry up to the top platform. For safety purposes the rehanging was undertaken under darkness when the library was closed to the public. It was just like Night at the Museum, but in a library...and without anything coming alive...but exciting nonetheless.

Collection Care staff were guided by tapestry experts from Textile Conservation Ltd. and we are really pleased with the result. Come visit the British Library and take a look for yourself!

Christina Duffy (@DuffyChristina)

Our next exhibition; Comics Unmasked, Art and Anarchy in the UK, opening on
May 2nd, will be a surprising one to many. It promises to challenge myths, expectations and stereotypes; and to explore subjects such as politics, violence, gender, sexuality and breaking social conventions.

The relatively good condition of most of the comics from our collection certainly challenged our expectations. For a number of readers, myself included, comics are seen as a relatively modern and populist genre, with striking graphics and minimum text. Conservators often associate anything modern (i.e. 20th century) and mass produced with poor quality paper; similar to the paper used for newspapers that becomes friable and yellows quickly when exposed to light. A few such items, one example shown below, did come to the studio requiring minor edge and tear repairs, but contrary to our expectations the majority of the comics were printed on good quality, often glossy, paper.

Matching tissue paper to support the damaged edge.

Conservation is usually very privileged in getting a preview on the items going into the exhibition, but not this time. Out of over 200 items prepared for display only a handful required conservation work. In the majority of cases the work was limited to flattening of folded pages followed by mounting or supporting a concertina style strip within a book.

Pressing objects between wooden boards

Comic strip opened up and supported within a volume

The first items to be prepared for the exhibition were not that recent either, one example being: ‘The Scourge of Monthly Expositor of Imposture and Folly’ from 1813 showing John Bull preparing for General Congress. This item also needed repair to the edges and mounting.

Concertina style comic strip before conservation

With objects from our collection being in ship-shape condition and one third of all objects in this exhibition coming from other institutions, conservation had a lot more work to do on loans. All items loaned had to be condition checked, some in-situ and others in the studio. Most of those worked on in the studio were paper-based, but we also condition checked unusual objects, such as Judge Dredd’s Helmet and Ally Sloper's Ventriloquist Dummy!

Ally Sloper's Ventriloquist Dummy

  Left: 

Sadly, we didn’t get any visits from Superman, Spiderman or Catwoman in the studio; but we did get to meet a ‘super heroine’ when the new poster advertising the exhibition was unveiled in the St Pancras Entrance Hall in mid-March!

The Comics Unmasked exhibition will be the UK’s largest exhibition tracing the history of the British mainstream and underground comics. It is a must for all lovers of comics, while for others it will be a trip down memory lane re-visiting well known comic characters, and meeting those we heard about but never met!

The exhibition poster showing a female posing after vanquishing a generic super hero

Iwona Jurkiewicz

The R. B. Kitaj Tapestry If not, not was rehung in the St Pancras Entrance Hall last Monday night after being removed for intense conservation cleaning. The tapestry is based on the painting of the same name by R.B. Kitaj, and measures 6.75 metres high and 6.75 metres long; it was the largest in the world when created by the Master Weavers of the Edinburgh Tapestry Company for the British Library. The tapestry had not been cleaned since its installation at St Pancras in 1997 and was displaying visible surface dust which had to be removed.

View of the British Library foyer with the Kitaj Tapestry hanging on the wall

 The Kitaj tapestry

The tapestry was taken down on 28 September 2012 by Collection Care staff guided by experts from Textile Conservation Ltd. who would undertake the mammoth task of cleaning at their studio in Bristol. 

The tapestry was taken down and rolled before being taken away for intense conservation cleaning

Samples of thread of various colour and locations were removed to monitor fading and colour change in the tapestry. A remarkable eight miles of  warp was threaded vertically between steel rollers during its production.

View of the vibrant threads on the back of the tapestry after being removed from the wall.

The tapestry was originally hung using lengths of beige hook and loop fastener. Six lengths divided into three pairs (10 cm apart) were stitched along the top edge. Along the sides were lengths measuring about 55 cm with gaps. These lengths were removed and the turned in sides were released by cutting and removing the stitching. It was here where casings from carpet beetle larvae and degraded moth cases were found. Luckily these were desiccated and no signs of damage were apparent. (Read more about how we deal with pests in a previous post: The Bookie Monster: attack of the creepy crawlies!).

Where to start with cleaning such a huge tapestry? With a hoover of course! The optimum level of suction was determined and the entire front and back surfaces were cleaned using a low powered vacuum suction. The hoover dust consisted of fine dust, brick dust and larger fibrous dirt found mainly on the front. This bag of dust has been retained by Collection Care staff for further scientific analysis. We are very serious when it comes to dust as you may have read in A-a-a-chooo! Collection Care’s Dust Busters.

Once clean it was important to ensure that no insects or eggs remained in the weave. The tapestry was rolled and taken to Harwell Document Restoration Services where it was placed in a freezer unit at -18°C for two weeks. It was fully defrosted over four days and taken back to Textile Conservation Ltd. where a new lining and Velcro hanging system were attached, as well as reinforcement work on any loose stitching. It was then rolled with interleaving layers of tissue and wadding and wrapped in Tyvek and bubble wrap before making its way back home to the British Library.

The tapestry was scheduled to be rehung on the opposite wall to where it was originally placed providing a wider range of viewing angles, and allowing visitors to get up-close to the tapestry on the stair levels. An impressive scaffolding system was erected and new battens were attached to the wall. The tapestry was hoisted up to the top platform after a thorough treble check that it was facing the correct way around!

Scaffolding assembled.

 The tapestry was placed on the upper platform when the scaffolding was fully installed

The Textile Conservation Ltd team took the top platform and began by attaching the top Velcro strips to the horizontal battens.

Conservators preparing for the reinstallation of the tapestry

The tapestry was then carefully lowered down in stages by scaffolders. 

Lowering the tapestry

This provided a controlled unrolling allowing Collection Care staff to hook the sides onto the battens without any air gaps.

Protective tissue paper was removed as the tapestry was unrolled.

 Protective tissue paper was removed as the tapestry was unrolled

When the scaffolding was removed a few days later the final result was terrific!

The R.B. Kitaj tapestry

The tapestry has regained its vibrancy of colour and is a magnificent feature in the British Library Entrance Hall. You can read more about the construction of the tapestry in this Telegraph article from 1997, and more about the artist in the National Galleries of Scotland website.

Christina Duffy

With St Patrick’s Day upon us it seemed fitting to take a closer look at some green pigments used throughout art and history.

Green earth pigment

Green earth pigment (or Terre Verte, Stone Green, Verdetta, Celadonite) is composed of clay coloured by iron oxide, magnesium, aluminium silicate, or potassium. The clay was crushed, washed and powdered. It was used since the time of the Roman Empire until the end of the Renaissance and was highly popular in medieval painting, especially for underpainting of fleshtones. An example is shown below in The Annunciation (1398-1311) by Duccio di Buoninsegna. Here faces were first painted with the green pigment and then overlaid with pink to give a realistic hue. In this case the pink has faded giving the impression of green skin. Green earth pigment was sourced from regions in the south of France and in Italy around Verona.

The Annunciation by Duccio di Buoninsegna: The Archangel Gabriel announces to the Virgin that she will be visited by the Holy Spirit and bear the son of God. Held at the National Gallery

Malachite

Malachite is a copper carbonate hydroxide mineral (copper(II) carbonate), and is green due to the presence of copper. It was used as a mineral pigment in green paints from antiquity until about 1800. It is fairly lightfast and very sensitive to acids meaning its colour can vary.

Brazilian malachite specimen highlighted by spheroidal rosettes of azurite (source) 

Artist Pietro Perugino used finely ground malachite in his 1503 painting Nativity to colour the bright green garments of the worshippers. 

Green pigment malachite is found in Nativity by Pietro Perugino (1448-1523)

Malachite has also been found in the King George III copy of the Gutenberg Bible, held at the British Library using Raman Analysis.

Gutenberg's (42-line) Bible: Opening of Proverbs. Johann Gutenberg, Johann Fust and Peter Schoeffer. Mainz, 1455 British Library C.9.d.4, f.1. Copyright the British Library Board

Cobalt green

Cobalt green is a moderately bright and translucent, but highly permanent, green pigment. The compound is formed by heating a mixture of cobalt (II) oxide and zinc oxide and was discovered in 1780 by Swedish chemist Sven Rinman. It can be mixed with other pigments and is also known as Rinman’s Green or Zinc Green.

Cobalt green (source)

Cobalt green was never very popular due to its high cost and weak tinting power. Researchers at the University of Washington have discovered that cobalt green possesses special magnetic properties and is now being used in the field of spintronics. Spintronic devices are used for computer storage and memory. Cobalt green has found success with spintronic devices as it can be used at room temperature while other materials must be super cooled.

Verdigris

This is a basic copper acetate and is formed when copper is exposed to acetic acid vapours.  The natural patina that forms on copper roofs is often called verdigris, but in non-polluted areas it is in fact malachite (basic copper carbonate).  In polluted areas, though, it is antlerite, a basic copper sulphate.  They are all similar colours so are easily confused, but verdigris in particular causes problems in manuscripts – it goes brown and can burn through the parchment and cause staining on adjacent folios. Verdigris has been used on murals in Pompeii, throughout the Renaissance and on medieval manuscripts including the Lindisfarne Gospels and Book of Kells.

Verdigris (source) 

Verdigris was found to be unstable and unwilling to mix easily with other pigments. In fact the great Leonardo da Vinci warned against its use in his treatise on painting and was leter replaced by the more stable Chrome Green.

Verdigris has been used to decorate the initials on f44v of the Lindisfarne Gospels shown here at 50x magnification (see here for more microscopy images of the Lindisfarne Gospels)

Viridian

Viridian was patented in 1859 and is a hydrated chromium(III) oxide Cr2O3 pigment described as a dark shade of spring green.

Viridian (source)

Viridian was used by Vincent van Gogh in many of his works including Café Terrace at Night, 1888 (Kröller-Müller Museum, Otterlo) and the Night Café (Yale University Art Gallery). Van Gogh to his brother Theo in 1888: "I sought to express with red and green the terrible human passions. The hall is blood red and pale yellow, with a green billiard table in the center, and four lamps of lemon yellow, with rays of orange and green. Everywhere it is a battle and antithesis of the most different reds and greens.” [1]

 Artist Vincent van Gogh (1853-1890) The Night Café, 1888. Oil on canvas currently at Yale University Art Gallery

In many cases a combination of pigments was used to create green colour. Recent analysis of the Sir Gawain and the Green Knight manuscript have shown that indigo (blue) over orpiment (yellow) was used in some areas, while a single mineral green was used in others.

 Sir Gawain and the Green Knight, Cotton Nero Ax folio 129v

Christina Duffy

Reference: [1] Vincent van Gogh, Corréspondénce general, number 533, cited by John Gage, Practice and Meaning from Antiquity to Abstraction