THE BRITISH LIBRARY

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

21 October 2014

Paper cuts: small but mighty!

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Hardly noticeable and barely bleeding, paper cuts are the mother of all library injuries. Anyone who deals with paper on a daily basis will have at some point suffered such an affliction. Paper cuts cause a seemingly out of proportion amount of pain due to the anatomy of our skin and the structure of paper. When very thin and held in place, a sheet of paper becomes inflexible and can exert very high levels of pressure – enough to slice through flesh! Yikes! Let’s go under the microscope to see what's happening...

Paper of the night  Paper cut
CC by Left: A single sheet of paper at x30. Right: Paper cut (image source).

Most paper cuts result from new sheets of paper held strongly in place. A rogue sheet may come loose from the pack but remain held in position by the rest of the tightly-knit sheets. In paper, more resistance is felt when a force is applied parallel to a sheet of paper. This has to do with the paper’s tensile strength. Tensile strength measures the ability of a material to resist rupture when force is applied to one of its sides under certain conditions. Held in place, the sheet of paper becomes extremely resistant to buckling, stiffens, and acts as a razor.

Dislocated sheet

CC by A sheet of paper that strays from the pack can cause serious paper cuts!

A paper’s edge may appear to be smooth and flat, but on a microscopic scale paper edges are jagged. Paper cuts leave a wound more like one from a saw than a knife (a miniature papery saw).

Copy book paper

CC by Pages from a copy book at x30 magnification. Fibres at the surface give paper a serrated edge. The black lines are page lines.

Paper cuts are remarkably painful. They usually occur in the fingertips, which have a greater concentration of nerve cells (neurons) than the rest of the body – an evolutionary trait to protect us during the exploration of our environment. Neurons send chemical and electrical signals to our brain, and some of them, called nociceptors, detect potential harm. Paper cuts stimulate a large number of nociceptors in a very small area of the skin. Shallow paper cuts don’t bleed very much so pain receptors are left open to the air resulting in continuous pain as the wound cannot clot and seal. As we continue to use our hands, the wound flexes open, continually distressing these neurons.

Not only do paper cuts part the flesh with a micro-serrated paper edge, but they also damage skin either side of the wound due to the composition of the paper. Pain receptors are continuously irritated by the combination of cellulosic wood pulp, rags, grasses, chemically-coated fibres, and bacteria that make up paper. Paper may also include other additives such as chalk or china clay to make the paper easier to write on. Sizing gives us a great variety of papers to suit the specific type of ink we wish to apply, but involves mixing many additives into the pulp to determine the correct surface absorbency.

Paper cuts from envelopes can be particularly stingy due to the layer of glue along the sealing tab. The glue is made from gum arabic, which although edible to humans, can pack a punch if embedded inside a wound. Gum arabic is the product of hardened sap taken from two species of acacia trees, and is also used as a binder for watercolour painting, and in traditional lithography.

Envelope adhesive x30

Envelope adhesive x200

CC by Gum arabic glue at x30 and x200 magnification coats the paper tab on an envelope. When the gum is moistened it forms a seal with the adjacent paper.

When skin closes around the paper cut these foreign particles become trapped inside causing a great deal of pain. This is why a cut from a razor blade is usually less painful than that from a paper cut: razor blades make clean incisions without leaving behind any foreign particles. It hurts initially, but the pain soon ebbs away. Bleeding caused by a razor cut helps to wash away any infection-causing particles, while paper cuts bleed very little (this also reduces your chances of getting any sympathy!)

Razor at x50

Razor at x200

CC by Razor blade at x50 (upper image) and x200 (lower image). The razor’s edge is smooth allowing a clean incision without introducing foreign bodies.

It might seem strange that sometimes needles for a flu jab require quite a bit of force to pierce the skin, yet paper (PAPER!) can slice through. This is due to the random orientation of collagen fibres in our skin allowing us to withstand pinpoint forces.

Point forces at x20

CC by Human skin feeling the pressure under a sharp pin.

Our skin does not have a comparable strength against shearing forces such as those exerted by paper, and so, we are susceptible to the small but mighty paper cut. Libraries can be dangerous places. Be careful out there!

Christina Duffy (@DuffyChristina)

 

Further learning:

Paper May Be the Unkindest Cut, Scientific American, Volume 306, Issue 3 , Mar 1, 2012 |By Steve Mirsky 

Why Do Paper Cuts Hurt So Much? Scientific American - Instant Egghead #25

 

09 October 2014

Burnt Cotton Collection survey enables digitisation prioritisation

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With the recent multispectral imaging of the burnt Magna Carta hitting the headlines following our blog post on the 800 year old Magna Carta revealing its secrets, there has been a lot of interest in the conservation work required to protect such items. The so-called “burnt” Magna Carta (Cotton charter xiii 31a) suffered fire damage in Ashburnham House in Westminster on 23 October 1731. This 1215 exemplification formed part of an exquisite library assembled by English antiquarian Sir Robert Cotton during his lifetime (1571-1631). Cotton’s library forms the basis of our collections at the British Library today, and a recent conservation survey of the burnt material has allowed us to categorise items based on their relative condition, enabling us to immediately identify items suitable for digitisation. This has vastly improved our workflow allowing digital access to a wider audience in a shorter time.

Burnt Magna Carta

Burnt Magna Carta seal

CC by The burnt 1215 Magna Carta suffered fire damage and subsequent interventive treatment. The vulnerable wax seal of the charter melted and distorted in the intense heat. 

In the Ashburnham House fire a quarter of the manuscripts were either damaged or destroyed in the blaze, and attempts to extinguish it exacerbated that damage. The documents suffered shrinkage and distortion, bindings were carbonised, ink was lost, soot and dirt was ingrained, tide marks formed on the leaves, and parchment (animal skin) gelatinised. Gelatine is the brownish end-product of a rapid degradation of parchment collagen. Remedial work caused further damage with many of the manuscripts broken up and rebound during salvage. Incorrect reassembly impacted on the codicological history of many of the manuscripts. The darkened gelatinous material which formed along the edge of the parchment was trimmed away from some manuscripts. Unidentified fragments were gathered and put into drawers.

The collection was untouched until the establishment of the British Museum in 1753, where over the coming years invasive treatments were recorded. To separate the leaves which had glued together by gelatinisation, about 40 manuscripts were immersed in a hot aqueous solution (likely to be ethanol in water). Incisions along the parchment edges were made to allow the leaves to dry flat under pressure. Despite the efforts, leaves remained brittle and fragile. Inlaying of parchment fragments into paper was completed in 1856, but a huge number of fragments remained loose and unidentified. While the edges of loose fragments were protected by this inlaying method, over time the degradation of materials caused further concern. The brittle fragments were susceptible to break with every page turn, and acidic paper in heavy volumes tended to cockle preventing the volumes from closing.

Cotton Tiberius A XII

CC by Cotton Tiberius A. XII. Parchment fragments were attached to paper in the ninteenth century and incisions were cut along the sides to allow the leaves to lay flat.

Our conservators surveyed 243 items from the Cotton Collection, including 21 paper manuscripts. Items were graded on their physical, chemical and overall conditions based on an assessment of the state of the binding and parchment substrate, and thus rated for treatment priority.

Grade

Condition

CC by From Figure 2 and 5 in The conservation of the burnt Cotton Collection in the Journal of the Institute of Conservation, 2013. Top: Results of the survey of 243 Cotton Collection volumes. Bottom: Pattern of damage where D (High degree of damage) accounts for 61% of the total items examined.

The nineteenth century treatments have been fundamental to the preservation of the Cotton Collection, and many items thought to be lost have since been rediscovered. The condition survey enabled us to quantify the damage and develop a strategy for the long-term preservation of the burnt Cotton Collection. Items identified as being fragile were immediately withdrawn from library use, while research to determine the best methods of stabilising and housing the items was undertaken. The use of analytical techniques such as near-infrared (NIR) spectroscopy for assessing the deterioration or parchment has enabled a better awareness of the nature and condition of these manuscripts. This information has helped to support the choice and realistic scope of conservation methods. In the case of the burnt Cotton Collection, the future project is now directed towards a preservation approach, including digitisiation and multispectral imaging, rather than an interventive conservation one.

Christina Duffy (@DuffyChristina), Imaging Scientist

 

Further reading

The conservation of the burnt Cotton Collection, Mariluz Beltran de Guevara and Paul Garside, Journal of the Institute of Conservation, 2013. Vol. 36, No. 2, 145 –161, http://dx.doi.org/10.1080/19455224.2013.815122

Collection Care fired up for BBC Four appearance, Christina Duffy: http://britishlibrary.typepad.co.uk/collectioncare/2013/08/collection-care-fired-up-for-bbc-four-appearance.html

Crisp as a Poppadom, Ann Tomalak: http://britishlibrary.typepad.co.uk/digitisedmanuscripts/2013/02/crisp-as-a-poppadom.html

‘Their Present Miserable State of Cremation' the Restoration of the Cotton Library, Andrew Prescott: http://www.uky.edu/~kiernan/eBeo_archives/articles90s/ajp-pms.htm

07 October 2014

800 year old Magna Carta manuscript reveals its secrets

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Ground-breaking multispectral imaging work of the British Library’s burnt copy of the 1215 Magna Carta has recovered text which has not been read in 250 years.

This work has been completed by British Library conservators and scientists in preparation for next year’s 800th anniversary of the sealing of the Magna Carta. The so-called ‘burnt’ copy of the Magna Carta is one of four original manuscripts from 1215 which survive. In February 2015, the four manuscripts will be brought together for the first time in history for a special 3-day event, which will allow further academic study of them side by side, as well as the once-in-a-lifetime opportunity for 1,215 people to view them together – you can enter our ballot to win your chance to be part of that event here.

Multispectral camera Colour image

Processed image

CC by Top left: The “Burnt Magna Carta” ready for multispectral imaging. Top right: A real colour image of a section of the charter. Bottom: A processed image of the charter enhanced to reveal text thought to be lost.

The British Library owns two of the original 1215 Magna Carta manuscripts (the other two are held at Lincoln and Salisbury Cathedrals). The story of the ‘Burnt Magna Carta’ (Cotton charter xiii 31a) held in our collections is a truly remarkable one of survival against all the odds. In 1731 it was damaged in the Cotton Library fire, and subsequently staff at the British Museum Library used 19th century techniques to try to flatten and mount it, which has contributed to its current condition today rendering the text very difficult to see.

The multispectral imaging of the burnt Magna Carta was conducted as part of a major project involving the reframing and scientific analysis of all the Magna Carta charters held in our collections ahead of the 2015 anniversary. The Collection Care team provided an initial examination of the original frames to determine their structure and composition. All original mounting materials in contact with the charters were tested using infrared spectroscopy, pH tests, and lignin tests to determine their stability and compatibility with new materials. Once the charters were removed from the frames, near-infrared spectroscopy and high resolution digital microscopy was used to investigate the condition of the ink and parchment as part of the overall condition assessment.

With the frames and glass removed there was a rare opportunity to employ the cutting-edge technique of multispectral imaging enabling us to virtually peel away the layers of damage currently affecting the manuscript.

Conservator Kumiko Matsuoka Conservation Scientist Dr Paul Garside

Conservator Gavin Moorhead Imaging Scientist Dr Christina Duffy
CC by Clockwise from top: Temporary housing is prepared to store the charter when removed from the frame; the original wooden frames are removed to enable access to the charter; the charter is released from the mounting; once the charter is free from the frame it can undergo condition assessment.

Burnt Magna Carta  Ink loss

CC by Left: The “burnt” copy of the Magna Carta, Cotton charter xiii 31a, is one of the four original manuscripts from 1215 which survive. Right: Much of the ink has been lost with only a few remaining initials (shown here at 50x magnification).

Multispectral imaging is a non-destructive, non-invasive imaging technique using different colour lights, including ultra-violet and infrared, to recover faded and lost text. A high-resolution camera is securely mounted directly over the charter, which is then illuminated with LED lights ranging from the ultraviolet at a wavelength of 365 nm, through the visible region, and right up to a wavelength of 1050 nm in the infrared region. The chemical composition of the material in the charter is varied (ink, parchment, etc.), and so reacts differently to the lights. We are able to see, and capture, additional information undetectable by the human eye.

CC by  An animated gif comparing the original colour and processed images. 

Ultra-violet colour image

CC by A colour UV image reveals regions of text which are completely faded to the naked eye.

Using this technology and expertise available to us in the 21st century, we are able to preserve the Magna Carta for the next 800 years and present these iconic documents in the best possible condition for visitors who come to see them during the anniversary year.

Multispectral data is still being processed and will be published along with other scientific data collected after the British Library’s exhibition ‘Magna Carta: Law, Liberty, Legacy’ which runs from 13 March – 1 September 2015.

You can see this Magna Carta manuscript alongside the 3 other surviving copies at the British Library on 3 February 2015 – find out more details and enter for your chance to win a place on www.bl.uk/magna-carta

Christina Duffy (@DuffyChristina), Imaging Scientist