The challenges of use and display

Books in a museum context have the particular challenge of being objects of study as well as objects of display. The beautifully decorated leather bindings which make the Founder’s Library such a grand historic interior also hold contents of great interest and therefore serve several purposes, both decorative and functional.

To commemorate the 400 years since the death of William Shakespeare, a small exhibition was put together last year at the Fitzwilliam Museum: ‘All the world’s a stage’: Shakespeare in Publication and Performance. Two of the books chosen1 to be displayed had loose or detached boards as well as worn corners and endcaps which would have affected their display. After consultation between the curator and the conservators, we decided to undertake conservation treatment firstly for the books to be displayed safely and look cared for but also, in a much bigger scale, to restore their flexibility and allow them to be consultated safely by readers.

Both books are second impressions of William Shakespeare’s work, printed in 1632. They are now in an early 19th century binding. The beautifully decorated bindings were covering a poorly made structure as some 19th century practices are known to put more importance into the aesthetic of the book rather than its mechanical function. The ’Russia calf’ leather used for the covering of the binding had become brittle over time due to its acidic nature. Joints are usually the first area to break down as they are subject to a lot of stress.

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Broken joint
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Brittle leather

We had two weeks prior to the exhibition to restore and even improve the accessibility of the content of the books by re-attaching the loose boards in a flexible and durable way. Re-attaching boards can be done in many ways and these books provide a good example of two different techniques we use.

The possibility to lift the gilded spine or not usually determines which technique we will use. If the spine is fairly easy to lift without falling into pieces, we will go for a re-back2, otherwise, we will reduce the lifting to a minimum and insert small strips of cloth underneath patches of leather. For the first book, the spine could be lifted so we decided to do a re-back.

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Cleaning the spine after lifting the original leather
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New endbands

After lifting the leather spine from the book and cleaning the spine from residues of old brittle glue, a wide strip of aerolinen3 was adhered to the spine. The aerolinen was then stuck with paste and EVA4 in the previously split boards in order to re-attach them to the text-block.

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Lifting the leather along the joints with a knife
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Adhere a hollow on the spine

The leather on the boards was lifted away along the spine edge and trimmed along the gold- tooled line. A hollow back5 made of Heritage Archival pHotokraft paper was adhered onto the spine and the book was re-backed with new toned leather.

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Re-back with new piece of toned leather

The original spine was then re-adhered onto the book and the missing areas on the spine leather were filled with Japanese paper and toned with acrylic paint to match the leather on the spine.

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After re-adhering the original leather on the spine
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After treatment

 

This treatment should be very long-lasting as the joints are now supported with aerolinen and new leather. Endcaps have also been restored in the process of re-backing and the original spine is now well supported.

The second book was quite another story. The leather was too brittle for the whole spine to be lifted away without losing the decoration and the sewing was in good condition which means that the spine didn’t need to be treated. Therefore, the leather was only lifted along the edges of the panels to allow tabs of aerolinen to be adhered to the spine and onto the boards to form a strong but flexible attachment.

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Aerolinen tabs extending from the joint
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Re-attaching the board

When these repairs were dry the original leather was readhered with a mixture of EVA and wheat-starch paste. The joints were then covered by a thin strip of Japanese paper6 to prevent slight cracks from developing. Paper repair patches were toned in situ using Golden’s acrylic paints and the whole binding was furbished with two light coats of Renaissance microcrystalline wax

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Adhering a strip of Japanese paper along the joint
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After treatment

This treatment is very efficient as it is much less time-consuming than a re-back but strong enough to hold the boards to the book when the rest of the binding is in good condition.

Both books have kept their aesthetical value which is extremely important in the context of historic libraries. They will still be able to fulfil their decorative role as well as being accessible and available for researchers and readers.

Lantern Project in the Founder’s Entrance (Part 1)

Founder’s Entrance lantern

The Fitzwilliam Museum is about to undertake a major building conservation project in the Founder’s Entrance. The focus will be on the lantern at the very top of the building.

The Founder’s building was first opened to the public in 1848 and the maintenance and preservation of the historic features is paramount. As a Grade 1 listed building, it is a priority to ensure it will remain resilient long into the future.

This project will look to address a variety of different aspects, including the replacement of some of the gutters and rain water pipes to prevent leaks. Repairs and replacement of some of the damaged curved glass and glazing compound (which holds the glass in place) will be done.  Conservation work to the internal decorative plasterwork and balustrade will also be undertaken.

Work has already begun in preparation for the scaffold installation: the sculptures that usually sit on the first floor landing have been boxed up and put into storage for safekeeping.

Moving day for the sculptures

From the end of April, a large scaffold platform will be installed across the whole of the Founder’s Entrance to allow access to the lantern.   This will mean that the Entrance Hall will need to be closed to visitors for a few weeks.  Once the scaffold is up and false ceiling put in, visitors will be able to visit the Hall once again.

This project will continue into early 2018. Please keep an eye on the Conservation and Collections Care blog for updates and photos.

Miraculous Madonna Make-overs: Preparations for the ‘Madonnas and Miracles: Private Devotion in Renaissance Italy’ exhibition, March 7th – June 4th, 2017

Every now and again, an upcoming exhibition at the Fitzwilliam Museum provides a welcome opportunity to carry out much needed conservation treatment on important works from the Museum’s collection of paintings. While these works may in fact normally be on display in the permanent galleries, and their general state of preservation is stable and acceptable, they have not necessarily received further attention from the Museum’s conservators since they came into the collection many years ago.

Paintings sitting in the same spot on a gallery wall year after year are not usually scrutinised in the same way as works emerging into the light after a long period in storage. It is often a challenge to find the time and opportunity to look at something very familiar with fresh eyes! However, for each of the five paintings that were given a session of careful TLC by staff and students at The Hamilton Kerr Institute before entering this special exhibition, the visual changes resulting from the treatments were more drastic than initially anticipated. While the size, style and colour scheme in these works are in one sense quite different, they are also all depictions of tender moments between the Virgin Mary and the Christ Child, painted to serve as devotional pieces for private worshippers in the 15th and 16th centuries. The removal of discoloured varnish layers, mismatched overpaint and centuries of dirt, transformed the images and revealed paintings of even greater colouristic beauty and refinement than could be appreciated previously.

Figure 1: Detail showing the back of the Virgin and Child during the removal of centuries worth of dirt. Brilliant colours were revealed within a trompe-l’œil frame, which surrounds a depiction of a fantastical marble slab.

The small Virgin and Child, tentatively attributed to Pietro di Niccolo da Orvieto (c.1430-84) although its iconography and decorative elements could suggest a considerably earlier date, has always been on display showing only its front. When it was recently taken off the wall for a closer assessment however, it became evident that the back is also well worth looking at. Just like the front, the back was originally prepared with a smooth, white gesso ground. A convincing trompe l’oeil frame was then painted to surround an image that was initially very hard to make out through the thick dirt layer that has accumulated through the centuries. As cleaning progressed, a brilliantly colourful, fictive marble slab emerged (figure 1).

The panel was subjected to x-radiography, which revealed how the timber structure was put together prior to the gesso application (figure 2). Four individual moulding profiles were nailed to the face of the panel with three to four nails along each side, which were bent to lie flush with the back prior to the gesso application, thus sealing them within the structure.

Figure 2: The x-radiograph of the Virgin and Child shows the x-ray opaque nails employed to attach the frame profiles to the main panel prior to the application of gesso, paint and gilding.

Although the front of the panel was also somewhat obscured by dirt and varnish, it had clearly been cleaned at least once in the past. Remarkably, most of the decorative scheme is still in rather good condition.

Even though the painting’s style owes much to the stylised and somewhat flattened depictions of the Madonna and Child in the Byzantine icon tradition, the Virgin’s outer garment, the maphorion, was still surprisingly dark and flat compared to the other passages in the painting (figure 3). However, infrared reflectography showed how folds were in fact present in the maphorion (figure 4). Dark overpaint obscured these folds to the naked eye, and careful removal of this non-original layer revealed the original, but worn, blue colour of the garment, painted with two paint layers containing the blue mineral pigment, azurite (figure 5). The top layer has rather large pigment particles, which would have resulted in a rich, velvety surface. Good quality azurite was deliberately employed coarsely ground, because with further grinding, it loses its intensity of colour and turns increasingly grey. The gritty surface resulting from the use of a coarse pigment would have rendered it vulnerable to wear and absorbent to later applications of medium and overpaint, leading to the darkening effect that gives the misleading impression of a black paint passage.

As a result of careful cleaning and a changed approach to display, the beauty of both front and back of this small, devotional object can once again be appreciated in the current exhibition, where it sits in a vitrine allowing both sides to be seen.

Seven painting conservators spent nearly 600 hours on careful conservation and restoration work up to the ‘Madonnas and Miracles: Private Devotion in Renaissance Italy’ exhibition, and if these madonnas have indeed become familiar faces on the walls of the Museum’s permanent collection, they are certainly well worth a second glance, restaged alongside other devotional objects for the duration of the show, which runs from March 7th to June 4th.

To read about the conservation work and painting techniques of the School of Botticelli tondo and of the Joos van Cleve Virgin and Child, follow this link to the Hamilton Kerr Institute Student and Intern Conservation Blog, where you can also read about the challenging process of creating a reconstruction of the Virgin and Child discussed above, using traditional artists’ materials and techniques: https://hamiltonkerrinstitute.wordpress.com/

All images in this post are the copyright of The Hamilton Kerr Institute, University of Cambridge

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RECOVERING AND RE-COVERING: Conservation of a fifteenth-century bookbinding

Books are something of an oddity in the context of a museum in that they are not only objects which we want to preserve for their historical significance but also machines which have a mechanical function to carry out every time a reader opens them. No one in his/her right mind would dream of cooking in a medieval pot or wearing a pair of eighteenth-century shoes – i.e. of using either object for its original function – but the medieval and eighteenth-century bindings in a library are expected to work to allow access to the texts they contain. Continued use, combined with the ageing of materials used in the construction of the bindings, eventually leads to boards becoming detached and sewing structures wearing to the point where they can break, so generations of bookbinders have repaired bindings as a large part of their work.
One of the incunabula (that is, books printed before 1500) in the Founder’s Library had been given a new spine in the late nineteenth century in order to reattach the front board. Unfortunately, the poor quality of the leather meant that the repair itself was deteriorating and the front board had become detached again. In addition, the previous repairer had used a large amount of hide glue on the spine of the book which prevented it from flexing. The result of this repair campaign was to give an early printed book a spine which would look much more appropriate on a nineteenth-century book. A large part of the interest of this binding was in what lay hidden beneath the previous repairs. As conservation work progressed, the book started to reveal elements of its making hidden for over a century.

The book as received, showing the original blind-tooled calfskin on the boards.
The book as received, showing the nineteeth-century leather on the spine.
The large amount of hide glue applied to the spine during the previous repair work prevented the book from opening properly. The image shows the maximum opening possible without breaking the spine!
The nineteenth-century paper paste-down on the inside of the front board appeared to be covering a much earlier sheet of parchment, which is just visible at the tail edge.

On close examination at the bench, it soon became apparent that the sewing structure might well be original and that endbands of braided alum-tawed skin, typical of Germanic bindings of this period, may well have survived under the newer leather on the spine. In addition, a narrow line of parchment was just visible, extending beyond the edge of the nineteenth-century paper paste-downs (the sheets of paper pasted to the inner surface of both boards). Depressions in the pastedowns also suggested that the original pattern of the cutting for the foredge corners of the boards (the free corners on the opening edge of the boards) was of the ‘tongue corner’ type rather than the mitred type suggested by the nineteenth-century repair patches. The ‘tidying up’ by the last repairer seemed to be obscuring a great deal of fascinating information.
After discussions with the curators of the collection, we decided that the need for repair provided a good opportunity to examine the structure of the book further and that the nineteenth-century material could be removed, saving annotations on the newer paper endleaves and the labels for future reference. Unfortunately, the nineteenth-century leather on the spine and at the corners of the boards was far too degraded to save and crumbled into powdery flakes during attempts to lift it. However, when the leather and hide glue on the spine had been removed, it was exciting to find that the original sewing structure and the original braided endbands had survived in a surprisingly good state of preservation, so much so that the whole structure could flex in an excellent opening arch as the original binder intended.

The spine cleaned of nineteenth-century leather and hide glue to reveal the intact sewing structure and braided endbands of a well-constructed early printed book.

Further investigation on the insides of both boards revealed that the original parchment board sheets were still in place and, further, that they were made from a recycled manuscript document which appears to have had at least six seals attached to it on parchment tabs in its original form – the slits for the tabs to pass through are clearly visible in the sheet on the back board (see the lower edge of the sheet in the image below).

Slits in the reused parchment on the inside of the back board suggest that the document originally had at least six seals attached with parchment tabs.

With the leaves of the book flexing from the spine-folds once again, it was also easy to see that the centre of each section had been reinforced by the binder with a folded strip of parchment to help prevent the paper leaves from tearing around the sewing holes. The parchment strips are made from manuscript waste too, although it is not yet clear whether they are from the same document as the board sheets.
The approach to repairing the book was to follow binding techniques of the fifteenth century rather than to re-apply inappropriate nineteenth-century methods. The front board was reattached and the attachment of the back board reinforced with linen braids, secured to the original raised bands with helical stitches of linen thread. The ends of the braids were left long so that they could be frayed out and threaded though the boards next to the original sewing supports to form a sturdy attachment. A slotted loose linen spine-liner was also added to prevent the new leather spine from being adhered directly to the backs of the sections and to form new inner joints in the repaired binding. The lining was carefully cut to fit around the endbands, which remain exposed as the original binder intended.

Linen braids and a loose linen spine-liner in place, ready for the reattachment of the front board.

New archival tanned calfskin was toned and pared to blend in with the original leather before being adhered with wheat-starch paste, again leaving the endbands exposed. The book was then put into a finishing press and strong cord was used to hold the leather tight to the spine and raised bands in the traditional manner during drying.

The re-backed book tied up with cord to dry.

The corners of the boards were re-covered with patches of the same leather inserted under the original covering material so that the tongue corners are visible once more. When the new leather was dry, the flanges of the linen spine-liner were adhered to the insides of the boards under the lifted edges of the manuscript waste board sheets, which were in turn pasted back into position.

Following conservation and repair work, this book is in safe condition to be consulted by researchers in the Founder’s Library. The opening is greatly improved and many original features of the binding have been revealed for the first time in over a century, allowing the book to give us many more clues as to its making and provenance.

The book after treatment.
The conserved book has a greatly improved opening.
The original recycled parchment manuscript sheets on the insides of the baords are clearly visible for readers.

Can you turn the heating up?

No.  Well, maybe.  It depends.

At the Fitzwilliam Museum, collections are kept in the best environment we can achieve, in order to prolong the lifespan of the objects and artworks; temperature is an aspect of museum management which not only is important for the comfort of visitors, but it also has a huge impact on the collections.

As the temperature remains low over the Winter months, we have to think carefully about how we heat the building.

Why might we pause before turning up the heating?  Bear with this brief physics lesson, if you can:

Increased temperature can affect a range a materials, including adhesives, metals and resins.  And, while it may not be visually obvious straight away, increasing temperature can increase the rate of deterioration of objects.

Temperature also has a direct impact on relative humidity (RH).  RH is the amount of moisture in the air in relation to the temperature, and is given as a percentage.  100% RH means that the air cannot hold any more moisture – this is when you would see water dripping down the walls!  The warmer the air, the more moisture it can hold; and if we were to turn up the heat in a room, the relative humidity would decrease causing the air to feel dry.

Organic materials, such as wood, contain water.  If the RH of the air is less than the moisture content in the object, then water will start to travel from the object to the air – this is when cracks can (literally) start to appear.

Panel painting which has curved as the wood reacts to the level of moisture in the air

So, if we turn the heating up, we have to introduce moisture into the air using a humidifier to keep the RH at the same level.  This will help prevent the objects drying out.

With older objects, there is often more evidence of the changing environments it has encountered, like this panel painting.  The wooden panel has curved as a reaction to the humidity levels around it.

At The Fitzwilliam Museum, we have the added complication of working in a Grade I building.  The Founders Building dates back to 1848, and there have been several additions since.  We have air handling units in some of the more modern galleries, which can control temperature and humidity.  But in the older galleries, we can only use heat to control the environment.

Environmental monitor measuring relative humidity and temperature

We have over 70 environmental monitors in the building, and they help us keep track of the environment in all the galleries and store rooms.

So, when we are asked if the heating can be turned up, we might say ‘yes’ but we have to do a bit of data analysis first.

Readings from an environmental monitor in Gallery I. It is showing the daily fluctuations in temperature and RH.

Welcome!

Welcome to the Fitzwilliam Museum Conservation and Collections Care Blog!

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The Fitzwilliam Museum has studios for the conservation of antiquities, applied arts, manuscripts and printed books, and works of art on paper and a scientific laboratory to carry out analysis on the collection. The Museum’s paintings are conserved at The Hamilton Kerr Institute, which is also a department of the Museum.

Conservators at the Fitzwilliam Museum work alongside curators, researching and investigating the materials and technology of the objects. They assess and record condition and undertake conservation treatment where necessary. The other important part of conservation work is collections care. This includes all the actions taken to avoid damage and slow down deterioration of the objects by controlling the environment around them.

Read more about the Fitzwilliam Museum.

Read more about Conservation and Collections Care at the Fitzwilliam Museum.