Collection Care blog

Behind the scenes with our conservators and scientists

4 posts from May 2014

20 May 2014

Discovery of a watermark on the St Cuthbert Gospel

A watermark of a post horn surrounded by a shield was recently discovered on the rear pastedown of the St Cuthbert Gospel (Add. MS 89000). The finding has just been published in the Electronic British Library Journal. The St Cuthbert Gospel is a late seventh century parchment volume and is the oldest intact European book. This Anglo-Saxon pocket gospel belonged to St Cuthbert of Lindisfarne (c. 635–687) and was discovered in 1104 in his tomb.

The pastedown, which is the endpaper attached to the inside cover board of a book, records the donation of the St Cuthbert Gospel (then known as the Stonyhurst Gospel) to the British Province of the Society of Jesus from the Reverend Thomas Philips, S. J. in 1769.


The front board of a book bound in dark brown leather. A rectangular decorated panel is in the middle of the board - it features a raised pattern in the shape of an interlacing vine, above and below which are rectangular panels of interlacing knot designs. The leather has deposits of dirt and small areas on the right-hand side of the board have become abraded.
St Cuthbert Gospel
A piece of cream paper pasted inside the back board of the book, covered with ten lines of Latin writing in dark brown ink. The paper is torn and folded in on the edges and at the corners. The number 91 is written in red crayon at the top of the piece of paper, above the first line of writing. The paper has some old dirt ingrained into its surface, which show the contours of the board and folds of the covering leather beneath.
Rear pastedown
A white representation of the piece of paper on the back board, showing only the outline of the watermark. The watermark is in the bottom right-hand corner. It consists of a cloud, inside which is an item in the shape of a hunting horn. A small tentacle or vine is coming out of the top of the cloud. Next to the cloud is a small design in the shape of a shoe with a high heel.
Watermark location

CC by Left: Front cover of the St Cuthbert Gospel. Centre: The rear pastedown showing a record of the donation: ‘Hunc Evangelii Codicem dono accepit ab Henrico Comite de Litchfield, et dono dedit Patribus Societatis Iesu, Collegii Anglicani, Leodii, Anno 1769; rectore eiusdem Collegii Ioanne Howard: Thomas Phillips Sac. Can. Ton.’ which translates to: ‘This Gospel Book was received as a gift from Henry, Earl of Litchfield, and given to the Fathers of the Society of Jesus, of the English College, Liège, in the year 1769, the rector of the college, John Howard, Thomas Phillips Canon of Tongres.’ Right: The watermark is located in the lower right hand corner

What are watermarks?

Watermarks are created by manipulating a piece of wire into a recognisable shape and fixing it to a paper mould such as the Japanese papermaking bamboo screen below.  Here the bamboo has been cut into strips and arranged into parallel lines called laid lines. The bamboo strips are held together by sewing thread at one inch intervals, which form the chain lines on a sheet of paper. Chain lines, laid lines and watermarks are visible when held up to a light source. Light can pass through watermarks easily because the paper thickness is reduced where wire is present in the mould.

The papermaking screen consists of two dark wood rectangular frames one on top of the other with a screen between them made from parallel strips of bamboo. A thin dark wood dowl bisects the top frame horizontally. The bamboo screen has lines of white stitching crossing it horizontally at regular intervals.
Paper mould

CC zero A Japanese papermaking bamboo screen

We typically notice watermarks on paper when they are held up to the light revealing a motif, initials or a date relating to the original paper mill. Watermarks are therefore useful in determining the provenance of paper and can help to identify its intended function. Watermarks can be difficult to image because they are often obscured by print on the page, or are located in the gutter (the space between the printed area and the binding).

An example of a partial watermark from a woodblock reprint dating to about 1476 is shown below. The reprint is of the Astronomical Calendar first published by Johann Müller (Regiomontanus) in Nuremberg in 1474 (British Library shelfmark IA.7). The watermark is found in the gutter with the other half located several folios later due to the ordering and cutting of the folios.

The gutter area of a book is shown horizontally. Grids of numbers are printed in black ink on both pages, and are coloured with yellow and red pigment on the top page. The watermark is in the margin of the top page, below the printed grid. It consists of a clover shape with three circular leaves. Two more circles like those of the leaves are positioned on each side of the central clover motif. Some of the watermark is obscured by the lower page.
Partial watermark in book gutter

CC by Watermark in the gutter of BL IA.7 when viewed through a light sheet 

When the page is adhered to a board on one side, such as the rear pastedown of the St Cuthbert Gospel, it is impossible for light to transmit and watermarks can remain undetected. A pastedown conceals the raw edges of the covering material and forms a hinge between the board and the text block.

A book bound in green leather with the front board open. The first page, the endpaper, is made from a single folded piece of cream paper, double the size of one of the book’s pages, the left hand side of which (the pastedown) is stuck to the inside of the board.
Pastedown example

CC zero An example of a front pastedown where one side of the endpaper is adhered to the front cover. Since the endpaper is fixed to the board it is difficult for light to penetrate and illuminate potential watermarks

The St Cuthbert Gospel watermark

A high resolution digital image of the pastedown was processed using ImageJ, an open source image processing software package. An image is comprised of a variety of layers or textures which can be separated. This allows pixels of interest to be isolated which may include faded writing, obscured text or watermarks. The watermark was revealed by converting the image from the standard RGB (red green blue) colour space into another space where tiny contrast differences were enhanced. The process of colour space analysis is fully explained in the publication: The Discovery of a Watermark on the St Cuthbert Gospel using Colour Space Analysis

The bottom right hand section of the rear pastedown, showing parts of the bottom six lines of writing in dark brown ink on cream paper.
No watermark observed
The same image, but with the colours reversed. The cream paper is now grey and black and the dark brown writing is shown in white. The watermark is shown in faint black lines.
Watermark visible

CC by Left: An image of the rear pastedown of the St Cuthbert Gospel where no watermark is observed. Right: The same image reveals a watermark in the lower right hand corner of the pastedown when processed into another colour space

Non-destructive science

Colour space analysis is being used at the British Library to enhance faded designs on binding covers, disclose watermarks and hidden inscriptions and to reveal text which has been chemically treated or erased. In many cases applying colour space analysis to certain multispectral images has proven successful.

Digitisation projects generate large amounts of high-resolution images which can be manipulated to discover hidden information without the need to access the item. This has significant implications for the long-term study and preservation of cultural heritage collection items. The rear pastedown in the St Cuthbert Gospel was formerly numbered f. 91 and is available to view on the internet as part of the Digitised Manuscripts website.

Christina Duffy (@DuffyChristina)

13 May 2014

Meet Our Adopt a Book Conservators

By adopting books at the British Library, donors have helped directly support the work of our conservators for over 25 years. We are very pleased to introduce our Adopt a Book conservators and tell you a little more about what they do in a new series of blog posts.

Kim Mulder, our new Adopt a Book conservator, is neither new to the British Library, nor new to conservation. She has already worked in the British Library conservation studio for 1.5 years on fixed term contracts and has extensive conservation experience. She previously worked in a number of institutions including Stedelijk Museum Amsterdam, Museum Boijmans-van Beuningen in Rotterdam, and The Netherlands Cultural Heritage Agency.

Kim has contributed significantly to several strands of our conservation programme including treatment on core collection items and running repairs. She has done extensive work on our War Office maps and also supports the Library’s major project to digitise some 60,000 maps and views in King George III’s personal collection by assessing their condition and managing any conservation treatment required.

Kim’s particular interest is in large paper objects. She says: “I like working on large format items because they come with their own set of challenges and parameters. I find them fulfilling to work on, but my training and experience allows me to work on a broad spectrum of objects.”

Kim has long blonde hair tied in a ponytail, and is wearing a grey scarf and cardingan. She is on the left side of the photo, sitting in at her workbench with her right side facing us. On her bench in front of her is a orange-brown map made of tracing paper, with red and black lines drawn on it. The map is weighted down with square weights covered in white, black and brown fabric. Kim is leaning over the bottom right corner of the map, which she is treating with a small black hairdryer held in her left hand. A metal scalpel lies on the bench next to her right hand.
Adopt a Book conservator Kim Mulder

CC by Kim working at her bench

Kim is delighted to be championing the scheme and working in the British Library, home to a vast and important collection of rare and priceless paper based artifacts. She is also happy to be back in London having fallen in love with the city ever since she spent a few months working in the British Museum as an intern.

In our next post we will be introducing book conservator Rick Brown who joined the Library as an apprentice in 1984 and has been involved with the Adopt a Book scheme since it first began.

About Adopt a Book

An array of eight brightly coloured greetings cards with book cover designs overlap in a fan shape. They lie on a light grey background.
Book-jacket gift cards

CC by Some of the book–jacket gift cards that donors receive; for the full range of 14 titles, see our website or check our British Library Shop

Funds raised through Adopt a Book have supported the work of conservators, enabling thousands of additional collection items ranging from books, manuscripts, maps, photographs, stamps and works of art on paper to be conserved, and also helping our conservators to acquire new skills and advance old ones to deal with more complex conservation challenges.

Following a re-launch of the scheme last year, books can now be adopted at the British Library Shop as well as online. By becoming a donor you not only directly contribute to our conservation work, but can also give a timeless gift to yourself or somebody else. For more information on the full range of adoptions available and benefits that more bespoke adoptions bring you, check our website

Iwona Jurkiewicz and Shimei Zhou

08 May 2014

Microscopy of the Lindisfarne Gospels, folio 3r

The Lindisfarne Gospels is one of the most magnificent manuscripts of the early Middle Ages. It was written and decorated at the end of the 7th century by a monk named Eadfrith who would go on to become Bishop of Lindisfarne and serve from 698 until his death in 721. An Old English gloss between the lines translates the Latin text of the Gospel and is the earliest surviving example of the Gospel text in any form of the English language. This translation was a late (mid-10th century) addition by Aldred, Provost of Chester-le-Street.

As one of the Treasures of the British Library the Lindisfarne Gospels undergoes strict condition assessments to ensure it is kept at ideal environmental conditions. Part of this assessment involves using microscopy to take a detailed look at the pigment behaviour. We posted some images in a previous post: Under the microscope with the Lindisfarne Gospels, and here we share some of the exceptional exuberance found on folio 3r.

A parchment page of illuminated text. The initial, in the upper left corner of the page, is the largest letter on the page, and extends down the left margin almost to the bottom of the page. It is decorated with swirling motifs, the heads of leopard-like animals, and interlocking birds. The main colours used for decoration are purple, light green, yellow, blue and black. There are two more letters on the first row, which are smaller than the initial but decorated in the same style. The rest of the text on the page, consisting of another five lines, is simpler and written in capitals in black ink. Some of the enclosed areas inside letters, such as A and B, are filled in with yellow, green and purple pigment. All these letters are surrounded by an outline of small red dots. A line of smaller, undecorated, red text runs along the top of each line, and an even smaller line of black text runs along the top of this
Folio 3r

CC zero Folio 3r of the Lindisfarne Gospels, Cotton MS Nero D IV. Examine in full detail here

The abstracted decoration found throughout the Lindisfarne Gospels is a spectacular example of Anglo-Saxon art. There are five major decorated openings in the manuscript, the first of which is found on ff. 2v – 3 and introduces the letter which St Jerome addressed to Pope Damasus. It was Pope Damasus who requested a revision of the Latin Bible text during the late 4th century. Folio 2v consists of an elaborate cross-carpet page and faces Jerome’s letter to Damasus in Latin with the opening Novum opus (New work). The intricate detail on this page has been interpreted as an act of personal spirituality and devotion. A few examples are shown below. Enjoy!

Top of folio 3r

A close-up of the second and third letters on the first line, showing their decoration of swirling knots and bird heads. The photo also shows the lines of red and black text running above them. There is a brown stain, caused by liquid, discolouring the parchment above the first letter.
Top of folio 3r
A close-up of two of the red letters (“p” and “I”) at 50x magnification. Under magnification the pigment appears yellow rather than red and both letters are covered with small cracks. The parchment background is grey-white and has a rough texture.
Folio 3r letter 50x
A close-up of a section of a red letter at 150x magnification. The cracks in the pigment are much larger in this photo and appear black in colour. The pigment again appears yellow rather than red.
Folio 3r 150x
A close-up of a spiral motif at 50x magnification. The spiral is drawn in black and its centre is coloured yellow. The yellow pigment is covered in cracks. There are red dots around the top and left sides of the spiral. The parchment background is grey-white and has a rough texture.
Folio 3r detail 50x

CC by Top: Upper section of folio 3r. Centre: Crackled pigment of lettering reading incipit prologus at 50x and 150x magnification. Bottom: Celtic-influenced spiral motif at 50x magnification

Centre of folio 3r

Tiny drops of red lead are also observed in early Irish manuscripts which heavily influenced the Lindisfarne Gospels. The Germanic zoomorphic style is evident with interlacing animal and bird patterns.

A close-up of the right side of the initial showing decorative animal heads which are purple with yellow noses and orange bodies. Sections of black text from the second and third rows are also shown. The black letters of the second row have areas filled in with purple and yellow pigment and are decorated with intertwining bird heads and necks. Around the initial decorative red dots are arranged in a diamond pattern; around the black letters red dots are arranged in straight lines.
Centre of folio 3r
A close-up of one of decorative animals on the initial at 20x magnification. The animal is drawn with strong black lines, and the orange pigment of its body is cracked. The parchment background is grey-white and has a rough texture.
Folio 3r 20x
The same area at 50x magnification. Cracks now show on an area of yellow pigment as well as on the orange. The purple pigment has an uneven, mottled texture.
Folio 3r pigment 50x
A close-up of the diamond pattern of red dots at 20x magnification. A single dot sits within each diamond. Under magnification the pigment appears yellow rather than red.
Folio 3r red lead 20x

 CC by Top: Central section of folio 3r from the British Library Catalogue of Illuminated Manuscripts with creature detail at 20x and 50x magnification. Bottom: Drops of red lead in a geometric pattern at 20x magnification

Bottom of folio 3r

Decorated initials exhibit yellow pigment (orpiment) bordered with drops of red lead. Craquelure is a network of tiny cracks caused by pigment shrinking due to age. When the disruption consists of perpendicular lines it is referred to as crackling.

An area of the fourth and fifth lines of text, which are written in black while the enclosed areas inside the letters are filled with blue, purple, green and yellow pigment. There are areas of brown liquid staining on both lines of text.
Bottom of folio 3r
An area of an illuminated letter at 30x magnification. The left side of the photo shows yellow pigment covered in dark cracks and decorated with red spots. A line of black ink runs vertically down the centre of the photo; the ink has a rough texture and is more thickly applied in some areas than others. To the right of the black line are three vertical rows of red spots. These are not perfectly circular but rather splodgy and uneven.
Folio 3r 30x
An area of the same letter at 100x magnification. Small pieces of yellow pigment are detaching where the cracks in it intersect with each other. The black ink sits unevenly on the parchment surface, and areas of it are shiny where they catch the light. At this level of magnification the parchment is not a uniform shade and there are dark flecks in the grey-white surface, which is very rough and uneven in texture.
Folio 3r 100x
A close-up at 20x of a letter “B” written in black ink with an outline of red spots. The surface of the black ink is very uneven, with a gritty texture. The enclosed areas of the “B” are coloured with light green pigment. A large flake of the green pigment is missing, and purple-coloured lettering from the reverse of the page shows through the parchment underneath. The parchment surrounding the letter is grey and discoloured.
Folio 3r pigment loss 20x
An area of the same letter “B” at 50x magnification. The light green pigment is mottled, and there are cracks around the area of loss. The letters showing through from the reverse of the page are clearly defined and overlaid with white cracks on the surface of the parchment. A line of black ink runs down the left side of the photo. It has an rough, uneven texture.
Folio 3r 50x

CC by Top: Lower section of folio 3r. Detail of decorated initals at 30x and 100x magnification. Bottom: evidence of loss of green pigment (verdigris or vergaut) from a decorated initial at 20x and 50x magnification. Text from the reverse (f. 3v) is shown through the parchment

For more details on the pigments used in the Lindisfarne Gospels see our previous post. The entire manuscript is digitised and available online here.

Christina Duffy (Twitter: @DuffyChristina)

06 May 2014

Recreating the Medieval Palette

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.

Five women wearing aprons stand behind a white table. The wall behind them is grey and a lot of light is coming into the room through a large window. Two women in the middle and far right of the photo are holding paintbrushes. All are looking down at the table, on which there are small pots of green, orange and blue pigment, as well as a large beaker containing paintbrushes. Also on the table are a camera and four pieces of paper with stripes in different shades of brown, yellow, red and blue painted on them.
Recreating the Medieval Palette

CC by 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.

A piece of paper with stripes in different shades of green, blue and grey lies on a white table top. Sitting on the piece of paper are a glass jar with a white lid and label containing a green powder, and a glass bowl containing a small amount of bright green pigment and a paintbrush. Behind the bowl and jar is a second, partially curled-up piece of paper on which two leaf motifs have been drawn in black ink.

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

On the left side of the photo six pots and dishes containing white, blue and yellow pigment sit on a table top covered in white paper. On the right side of the photo, on the same table top, two hands are grinding white pigment on a glass tile using a solid glass tool shaped like a doorknob.
Lead grinding

CC by 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.

A right hand mixes yellow and blue pigments on a glass tile while a left hand holds a glass jar lid above the tile. A dish of yellow pigment with a white-handled metal spoon in it sits in the bottom right corner of the photo. In the background of the photo are a jar of blue pigment and two overlapping pieces of paper, the uppermost of which has horizontal yellow stripes painted on it.
Mixing saffron


Two pieces of white paper lie on a grey background. Both are painted with vertical stripes in different shades of blue, which have pencil annotations above and below them.
Painted-out medieval blues

CC by 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!


Four people bend over a table, the surface of which is covered with cameras, notebooks, feathers and beakers of water. The two people closest to the camera are writing in black ink on pieces of white paper.
Reed pen


Two pieces of paper lie on a white table top, along with a quill pen, a jar of water and a block of carbon ink. The block of ink is rectangular in shape and is decorated with a white and yellow picture of a person in traditional Chinese dress. The two pieces of paper have horizonal stripes of different inks drawn on to them, and are annotated in the same inks. The annotations state what kind of ink (ivory black, lamp black, bone black) it is and what kind of pen it was applied with (quill, reed).
Quill pen

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

Two pieces of paper on a white table top, surrounded by two jars of pigment and a beaker of water. The pieces of paper are covered in colour samples, mainly taking the form of stripes and solid blocks of colour, though there is also a pattern of interlocking circles and a picture of a bird.
Colour sample sheet

  CC by 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