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

07 December 2020

Lotus Sutra Project: Storage Solutions

Paulina Kralka and Marya Muzart

The Lotus Sutra Manuscripts Digitisation Project at The British Library, is a multi-year project aiming to conserve and digitise almost 800 copies of the Lotus Sutra scrolls in Chinese, with a view to make images and information freely accessible on the International Dunhuang Project (IDP) website. These manuscripts come from a small cave in a Buddhist Cave complex near Dunhuang, in Northwest China, where tens of thousands of documents, paintings and artefacts dating from the late 4th to the beginning of the 11th centuries were discovered in 1900. Out of the 800 manuscripts included in this project, a large portion of them need conservation work.

Depending on the scrolls’ condition, treatment can range from surface cleaning and minor repairs, to lengthy mould remediation and intricate infills to ensure that they are safe for digitisation. With manuscripts in varying states of preservation and size, ranging from 10 centimetres to almost 14 meters in length, they have very different housing needs. Addressing these various housing requirements is part of our conservation work. We take into account our existing storage facilities, and come up with solutions that are best suited for long-term preservation of the collection but are also feasible within the time and budget of a digitisation project. This poses an interesting challenge to us as conservators.

The storage facility for scrolls at the British Library consists of white open shelving or glass enclosed wooden cabinets holding individually boxed scrolls.

Picture 1: Our storage.

Here a conservator is placing a scroll into a pigeon hole. Some of the cabinets have individual pigeon holes for each scroll with the shelfmark noted.

Picture 2: Close-up of the pigeon holes where the scrolls are stored.

The majority of scrolls that arrive in our conservation studio have never been treated before. They are usually tightly rolled on their own or around a thin wooden roller attached to the last panel. This causes tensions and leaves the scroll unsupported where it then becomes prone to distortions, creasing and further mechanical damage when handled. Research and practice show that the larger the rolling diameter, the less likely the scroll is to develop creases and cracks. In order to address this, we always place the scrolls on increased diameter cores after treatment has been completed. These cores are made from acid free cardboard tubes with a 5.5cm diameter, that we cover with a layer of xuan paper 宣纸 using wheat starch paste as an adhesive. The cores help reduce the tensions caused by a scroll being rolled too tightly and also provide it with proper support during handling and storage, minimising the risk of further damage. In addition, each scroll is wrapped in a protective layer of xuan paper, which prevents dust accumulation and surface abrasion.

Here a conservator is unravelling a scroll on a red desk with the aid of a scroll core.

Picture 3: A scroll being handled with the help of a core.

When rolled onto the 5.5cm cores, some of the longer scrolls in the project (typically those over 10 metres long) no longer fit into the pigeon holes of our existing storage. In order to enable the scrolls to still be stored in the existing storage facilities on an increased diameter core, whilst having enough space for safe handling, we have successfully developed a technique of hand-making cores with a smaller diameter of 3.5cm, composed of archival grade kraft paper and wheat starch paste.

A comparison of two scroll cores: the core on the left is wider at 5.5cm while the core on the right is 3.5cm.

Picture 4: Left, the 5.5cm core and right, the 3.5cm core which we hand-make for very long scrolls.

And what about the shortest surviving fragments? They are usually severely damaged. To prevent possible dissociation and further weakening of the paper, we encapsulate them in Melinex pockets. Melinex is an archival grade, glass-clear, thin polyester sheet, which not only helps us protect such delicate fragments but also allows them to be stored flat within custom made folders. Scroll fragments in Melinex are safe and easy to handle as both sides can be easily accessed, whether by our imaging staff during digitisation, or researchers wishing to examine the manuscripts in the reading rooms.

A conservator is encapsulating a scroll fragment between two Melinex sleeves so the scroll lays flat.

Picture 5:  Encapsulation of a scroll fragment in Melinex.

We are lucky that a large number of scrolls in our collection survive with their original wooden rollers still in place. In order to house the rod safely, whilst simultaneously providing appropriate support for the scroll, we have modified our standard core to create a custom-made clamp which fits the original roller inside and increases the rolling diameter. The cardboard core is cut in half; an intricate system of Japanese paper tabs is then pasted down to allow it to open and close smoothly; and, finally, a small groove is cut out to facilitate accommodating the scroll and rolling it onto the core. This clasp core design is adapted from the traditional Japanese wooden roller clamp, known as futomaki 太巻 or futomaki jiku 太卷轴, used for hanging scrolls, but is much more lightweight and economical!

The clasp core design, which safely houses scrolls with the original rod still attached. The clasp core design, which safely houses scrolls with the original rod still attached.

The clasp core design, which safely houses scrolls with the original rod still attached.
Pictures 6, 7 & 8: The clasp core design, which safely houses scrolls with the original rods still attached.

In some instances, the original wooden rod is detached from the scroll, which creates another storage challenge. To avoid any dissociation, we always aim to store the rod together with the scroll. In order to achieve this, we have created small foam inserts that fit the roller in them and placed them inside standard cores. We found that polyethylene pipe insulation tubes are well-fitted for the purpose! Thanks to the Oddy tests carried by our conservation scientist Paul Garside, we know they can be safely used with our collection. The tube is cut in half and hinged on one side with Filmoplast SH cotton tape to allow for smooth opening and closing. The rod, wrapped in a protective layer of xuan paper, is placed inside and secured in place with pieces of cotton tying tape, threaded through small slits cut in the tube. The insert fits inside the core quite snugly, so we place a small tab on the bottom of the tube to facilitate access.

The foam tube which houses the detached original rod with the scroll. This tube is split open showing how the tape is threaded through small slits in the tube.

The foam tube which houses the detached original rod with the scroll. This foam tube is split open to reveal the inside.

The foam tube which houses the detached original rod with the scroll. 

Pictures 9, 10, 11 & 12: The foam tube which houses the detached original rod with the scroll. 

These storage solutions show how our work doesn’t end in the conservation studio. To ensure that the collection is well-preserved for future generations, we have to think beyond just the treatment of the object. This project has enabled us to challenge ourselves in thinking outside the box and approach the various storage issues with innovative solutions. 

25 November 2020

Lotus Sutra Project: Scroll with Blue Cover

Marya Muzart, Digitisation Conservator, International Dunhuang Project

Digitised scroll after treatment showing a blue cover on the scroll.

Picture 1: Close up of digitised scroll after treatment.

The Lotus Sutra Manuscripts Digitisation Project at The British Library, is a multi-year project aiming to conserve and digitise almost 800 copies of the Lotus Sutra scrolls in Chinese, with a view to make images and information freely accessible on the International Dunhuang Project (IDP) website. These manuscripts come from a small cave in a Buddhist Cave complex near Dunhuang, in Northwest China, where tens of thousands of documents, paintings and artefacts dating from the late 4th to the beginning of the 11th centuries were discovered in 1900. Out of the 800 manuscripts included in this project, a large portion of them need conservation work. This blog post covers the treatment of Or.8210/S.3796 which measures over 10 metres long.  

What is particularly striking about this item is the blue cover or protective flap at the beginning. Whilst it bears a few stains from water damage, the colour is incredibly vivid considering the age of the item. It is unusual in this project to see scrolls which are 100% complete, from the front cover to the very last panel, so having the front cover present, in addition to its striking colour, makes this item quite special. In addition, part of the thin wooden stave on the cover is still present, a silk tie would once have been attached to this, however it is now gone. 

The use of blue paper (typically dyed using indigo) for sutras grew in popularity in China from the Tang dynasty (618–907 CE) onwards, it flourished in Korea and Japan around the same time and can also be found in other cultural traditions beyond East Asia. By the end of the Dunhuang period, and in later Chinese tradition it became common to use silver or gold ink on dark blue paper for the finest manuscripts [1]. See this fragment of scroll Or.8210/S.5720, which is part of our wider collection, as an example. 

Re-use and recycling of paper was a common practice carried out by the monks in Dunhuang [2]. It is possible that the cover of Or.8210/S.3796 was sourced from some left-over paper which had previously been used for one of the finer sutras written on blue paper. 

Recto before treatment showing a torn scroll with Lotus Sutra characters

Picture 2: Recto before treatment.

Verso before treatment showing a damaged and torn scroll laid out on a red table.

Picture 3: Verso Before Treatment.

The losses which you can see in the before images were a result of historical rodent damage, when the scroll was examined closely small teeth marks could be seen. As the damage occurred when the scroll was rolled, there is a repetitive nature to the losses which get smaller as we move away from the beginning of the scroll. Due to the presence of these numerous large losses conservation treatment had to be carried out in order to stabilise the scroll for digitisation.  

The first step to treatment was creating a blue repair paper to match the cover. At the IDP conservation studio our usual repair papers are hand dyed in relatively large batches using fabric dye, this is so that we always have lots of different tones and colours at hand. However as blue isn’t a typical colour we come across in this project, some experimentation had to be carried out in order to get the correct blue shade for the repair paper.  Dyeing was tried at first using the usual fabric dye, however the right blue hue still wasn’t accomplished after a few attempts, so I decided to tone the paper using a diluted acrylic paint instead, which was more successful and efficient. 

Some repair samples from experimentation laid out on a table.

Picture 4: Some repair paper samples from experimentation.

Finding the correct colour when custom toning repair paper is typically a matter of trial and error. Once I had found the correct combination of colours, I used a Japanese paper which had previously been dyed a yellow tone and this created the perfect base for applying the diluted blue acrylic wash. As the verso of the cover is lighter, once dry, the blue repair paper was then lined onto a lighter, yellow toned paper using diluted wheat starch paste. My custom toned repair paper was then used to infill the losses present on the cover of the scroll. For the remaining losses throughout the scroll, a yellow toned paper was used, this was a much easier source out of our existing repair paper collection!  

As you can see from the after images, the scroll can now safely be handled and digitised by trained internal staff. It is a unique item in the project, which was a pleasure to work on. All in all, a successful treatment! 

The digitised scroll is available to be viewed via this link thanks to Jon Nicholls.

Close up after treatment showing previously missing areas filled in.
Picture 5: Closeup after treatment.

Scroll after treatment with no tears or missing areas, laid out on a red table.

Picture 6: Scroll after treatment.

[1]https://www.bl.uk/collection-items/chinese-buddhist-sutra-on-indigo-dyed-paper 

[2]   Rong, X. (2013) . Eighteen Lectures On Dunhuang. Trans. by Galambos, I. Boston: Brill, p.123 

22 October 2020

On light: conserving material for our exhibition Unfinished Business: The Fight for Women’s Rights

Alexa McNaught-Reynolds, Conservation Exhibition and Loan Manager

Two of the items selected for display in our exhibition: Unfinished Business: The Fight for Women’s Rights appear to be in good condition but have vulnerabilities that may not be immediately obvious. In Conservation we strive to understand every component of an object in order to recommend the best course of action for their long-term care.

Item 1. NEWS.REG170: Daily Mirror front cover: Tuesday 28th March 2017

Vulnerability: newspaper is not made to last

This is an important item in the exhibition, highlighting how strong working women are still sometimes represented in the media today. Newspapers are produced from poor quality wood pulp that is inherently unstable due to something called lignin, and they are not made to last. Lignin makes the paper acidic and when placed in direct sunlight, as many of you will have seen, newspapers turn yellow and become brittle very quickly.

Controversial front page of the Daily Mirror on Tuesday 28th March 2017 showing Theresa May and Nicola Sturgeon. The headline reads 'Never mind Brexit, who won Legs-it!'

Figure 1: Controversial front page of the Daily Mirror on Tuesday 28th March 2017 (NEWS.REG170)

We strive to protect our newspaper collection by storing them in alkaline buffered material, in a stable environment free from exposure to light sources. These actions significantly slow the degradation process.

But what about when one is requested for exhibition? While we are familiar with the vulnerabilities of newspaper generally, we are not sure how stable the media will be under exhibition conditions. The exhibition environment is very stable and the newspaper is subjected to low levels of light. While light level is low, with no UV, and the time is restricted, we are not sure how much of an effect this limited light exposure will have on the media.

In order to get a better understanding of how the media will fair under exhibition conditions, we will be monitoring this item closely. To do this, we are measuring the colour by using simple colorimetry. This is completed with 'Lab*' colour measurements which is a method of representing colour using numerical values, in a similar way to the more familiar RGB or CMYK systems. One of the particular advantages of the Lab* system is that it is based on the way in which the human eye and brain observe colours and determine differences between colours. 'L' represents lightness, from 0 (pure black) to 100 (pure white), while 'a' measures the green-red axis (negative values are green and positive values, red) and 'b' measures the blue-yellow axis (negative values are blue and positive values, yellow). The system is capable of detecting colour changes smaller than the human eye can observe, and so gives us another tool to help us provide the best possible stewardship for the items in our collection.

Controversial front page of the Daily Mirror on Tuesday 28th March 2017 showing Theresa May and Nicola Sturgeon. The headline reads 'Never mind Brexit, who won Legs-it!' This image has been labelled with yellow lines and numbers showing where colour measurements were taken.

Figure 2: Front page of the Daily Mirror with areas marked in yellow indicating where colour measurements were taken.

Highlighted in the image above are the areas where the colours were measured. The same areas will be re-measured at the end of the exhibition. This will detect any colour changes that have happened (hopefully none) and will inform the future display limitations of this item and for other similar contemporary newspapers.

Item 2. Add MS 88899/6/13:  Greenham fence wire from the Angela Carter archive

Vulnerability: highlighter ink loses colour under light exposure

This item is a piece of wire cut from the perimeter fence of RAF Greenham Common Airbase during anti-nuclear protests by the Women's Peace Camp and sent to the novelist Angela Carter who was against nuclear weapons. It was attached to a record card through two punched holes in the centre with typed notes above and below the wire.

Greenham fence wire piercing a white flash card from the Angela Carter archive with high-lighted typed message.

Figure 3: Add MS 88899/6/13:  Greenham fence wire from the Angela Carter archive with highlighted typed message.

Although the item itself is in good condition, highlighter pen was used over the top of the typed message. Highlighter pens contain fluorescent colours which are notoriously light sensitive; they will not retain their colour over extended periods of light exposure. For this reason, we will be displaying this item at our exhibition under low light levels but we will also be limiting future display in order to preserve the bright colour.

At the British Library we aim to make everything as accessible as possible so that everyone can enjoy the collection and see the items in their original condition. However, in order to preserve the collection some items do need to be restricted for various reasons, such as fragile condition, or in these cases, to limit their light exposure and preserve the bright colours for future researchers to see.  Although this means that some items can only be able to be exhibited for short periods, there are alternative solutions for display. For items that were mass produced or have multiple copies, it is possible that a replacement can be found. When an item is unique or other copies are not available, we can suggest a high-quality facsimile be made, this way the viewer can see the uninterrupted exhibition story. In this way, we can maintain the integrity of our collection for as long as possible, as well as finding ways for everyone to enjoy it in the meantime.

Fortunately, both original items will be displayed in ‘Unfinished Business: The Fight for women’s Rights’.