Walking on eggshells: conservation treatment on Roman glass

By Adelheid Hansen, Conservation Intern in the Departments of Antiquities and Applied Arts at The Fitzwilliam Museum. Graduated from the Ceramics and Glass Conservation Programme at West Dean College.

 

In conservation, an important principle is to protect an object from (further) damage. Conservators often have to find creative methods to ensure an object is not harmed by treatment.

One of my tasks as a conservation intern at the Fitzwilliam Museum in Cambridge was to conserve a 14 centimetres high Roman glass unguentarium (thought to have been used for perfume or oil), which was found in Cyprus and had entered the museum collection in 1888.

The unguentarium had many issues:
  • There was a kidney-shaped area of loss with a sharp piece sticking out (fig. 1)
  • There were several running cracks, one running halfway around the body! (fig. 2)
  • There was iridescence. Iridescence, as beautiful as it can be, is a sign of degradation and can detach itself from the glass surface in the form of flakes
  • There was dirt inside
  • And last but not least, due to glass degradation, the remaining glass was extremely thin, as thin as, or even thinner than, an eggshell.


Fig. 1 Unguentarium before treatment, front side, showing kidney-shaped area of loss


Fig. 2 Unguentarium before treatment, reverse side, showing running crack halfway around the body

Roman glass usually consists of a mixture of sand, soda and lime. When buried in the earth and in contact with water, the soda can dissolve and leach out, causing degradation of the glass. When left long enough, the whole object could disintegrate and disappear.

Treatment plan

The running crack needed stabilising and also the sharp piece sticking out needed protection.

When glass is that thin, it is not an option to introduce an adhesive into the running crack, because it can make the crack lengthen and even split the vessel into two halves.

Therefore, we decided to try to stabilise the unguentarium by attaching a fill from the inside to the missing area. This way, the cracks would be supported and also the dirt on the inside would be protected. Dirt can tell a great deal about the history of an object, for instance about the area where it was found, or it could hold a residue of the previous contents of the unguentarium. When removed, this history is lost; therefore, we decided that the dirt should not be removed.

Japanese tissue with a coating was chosen to make the fill. Japanese tissue is strong and lightweight, so the weight of the fill would not cause further damage, and the coating would provide support for the Japanese tissue. This way it would be possible to make a strong and thin fill.

But since the glass was so extremely thin, no mistakes were allowed and attaching the fill had to be right the first time. Therefore, it was necessary to practise on another object.

Practice

Finding a replacement object to practise on was not difficult, because the discussion about the glass being thinner than an eggshell inspired me to practise on an actual eggshell. After a few attempts resulting in broken eggshells, I managed to carve a similar shaped hole in the eggshell, to the hole in the unguentarium, using a scalpel (fig. 3).

Fig. 3 Shape carved out of eggshell with scalpel

I tested two adhesives to use as a coating on the Japanese tissue. Klucel G, a water-soluble adhesive, could not provide enough rigidity for the Japanese tissue. Instead, a 10% w/v solution of Paraloid B72 in acetone was used to make the coatings (fig. 4).

Fig. 4 Solution of 10% w/w Paraloid B72 in acetone

Next, I needed to develop a method for how to shape the Japanese tissue. Fortunately, I found a bottle in the lab that had a similar curve to the missing area of the unguentarium. I then applied de-ionised water to a piece of Japanese tissue with a glass pipette. The wet Japanese tissue was placed on the glass bottle and I carefully manipulated it in such a way that there were no creases in the paper (fig. 5). Care was taken not to stretch the tissue too far, as this would cause thin sections in the tissue. The bottle was placed on a radiator to accelerate drying time.

Fig. 5 Piece of Japanese tissue drying on glass bottle

After the Japanese tissue had dried, I carefully removed it from the bottle. The tissue now had a curved shape. I then placed the now curved Japanese tissue on a Melinex (polyester film) sheet and applied a solution of 10% Paraloid B72 w/v in acetone with a glass pipette (fig. 6). After curing, new layers of the Paraloid B72 solution were applied in the same way, until the Japanese tissue had the right strength.

Fig. 6 Applying layers of Paraloid B72 with glass pipette to shaped Japanese tissue

I cut the curved and coated Japanese tissue slightly larger than the missing area. Unfortunately, it proved to be impossible to insert the fill in one piece, and therefore I cut the fill into two halves.

Fig. 7 The fill is too big to be lowered into the egg in one piece

The fill had to be lowered into the unguentarium and lifted up in order to be able to bond it behind the missing area (the surface on the outside of the bottle was too fragile to have adhesive applied to it). Therefore, I attached two sections of string to each half. First, I tested masking tape to attach the strings to the fills (fig. 8). However, masking tape would be difficult to remove while the fills were adhered to the glass. Even the slight force needed to remove the tapes could cause the glass to break. I also could not use solvents to remove the tapes as this could compromise the coating of the fill.

Fig. 8 String attached with masking tape

I then tested a solution of 5% w/w Klucel G in de-ionised water to attach the strings (fig. 9). Klucel G is soluble in water which would not compromise the coating, however, Klucel G proved not to be strong enough. Therefore, cyclododecane was used to attach the strings. Cyclododecane is a wax that will sublime over time and disappear, so no solvents or force would be needed to remove the strings. They could simply be left until they fell off.

Fig. 9 Strings attached with Klucel G

For this part of the process, I needed an extra pair of hands. Julie Dawson kindly offered to help me. We frayed the ends of the strings to enlarge the area of contact. Cyclododecane was heated au bain-marie under extraction and was applied to the frayed strings on the fills with a brush. Each half of the fill now had two pieces of string attached and was ready to be attached behind the missing area.

The first half of the fill was lowered into the egg and then raised by gently pulling up the strings. One of us used acetone on a small brush around the edges of the fill to activate the Paraloid B72 and to adhere the fill to the egg, while the other kept the strings being pulled up. This process was repeated with the second half of the fill (fig. 10).

Fig. 10 Strings attached with Cyclodecane, fill complete

Fig. 11 Tools used for egg-practice

 

Treatment

The method proved to be successful and could now be executed on the unguentarium. Because all the stages of the treatment were rehearsed on the egg, attaching the fill to the real object went smoothly (figs. 12 and 13).

Fig. 12 Unguentarium during treatment

Fig. 13 Unguentarium during treatment

The end result was a stabilised unguentarium (fig. 14).

I thoroughly enjoyed the process of testing various options on an eggshell and finding a solution that was beneficial to the unguentarium. I am very grateful to the conservation team of the Fitzwilliam Museum for giving me this learning opportunity.

Fig. 14 Unguentarium after treatment

 

By Adelheid Hansen, Conservation Intern in the Departments of Antiquities and Applied Arts at The Fitzwilliam Museum. Graduated from the Ceramics and Glass Conservation Programme at West Dean College.

Acknowledgements to:

  • Jennifer Marchant, for supervising my project
  • Julie Dawson, for helping me with the cyclododecane
  • Elsbeth Geldhof, for teaching me about the many uses of Japanese tissue in conservation
  • Edward Cheese and Gwendoline Lemée, for providing the Japanese tissue.

 

Lantern Project in the Founder’s Entrance (Part 5)

What lies beneath…

As with many conservation projects, new discoveries are made as work progresses.

The contractors for the lantern repairs, Brown & Ralph, have provided an explanation as to what happened when they looked below the surface. What was revealed showed why this project is so crucial for the future of this historic building:

Having removed the original weather-proofing from the lantern, several areas of suspected decay to the timber structure beneath were identified. Upon further investigation, it was found that some timbers were rotten and the structure weakened in these areas. This is thought to be the result of long term minor water ingress.

“Once the areas were identified, the Museum’s Structural Engineer worked with carpenters from Brown & Ralph to design a repair to the timber structure. This involved propping critical load-bearing timbers, cutting out rotten timber, forming joints and ‘letting in’ of new timber.

“The repairs were all worked out individually to cause as little interference as possible but maintain maximum strength throughout the structure. B&R were able to carry out all the repairs employing traditional timber joints. The replacement timber (some with sections as large as 300mm x 150mm) was selected from a trusted saw mill and used slow grown Douglas Fir to mimic the timber used when constructed originally.

“As a result, the structure is back to full strength whilst maintaining the original aesthetics. It has since been re-boarded with similar Douglas Fir.”

When fashion transforms the truth

As part of Cambridge’s Festival of Ideas 2017, I took part in a series of behind-the-scenes talks on how we investigate the ‘true’ nature of museum objects. As the event was so successful and attendees showed a lot of interest in the subject, this blog post is aiming to share the story of the objects I discussed on that occasion.

What secrets or lies can we unveil, by which means can we do that, and how far can we go into our understanding of past practices? Some objects lead us into exciting journeys and this is the case of two manuscripts fragments from our collection (MSS 293a and 293b1).

MS 293a (432 x 402 mm)
MS 293b (356 x 376 mm)

These two beautiful and quite peculiar illuminated fragments come from the Royal Monastery of St Thomas in Avila, Spain, and were presented by the Friends of the Fitzwilliam Museum in 1918. By taking different approaches – those of a curator, a conservator and a research scientist – to investigate the truth of these objects, we can retrace their story and reveal some of their secrets.

Historical context and iconography

The description of the image is the first step in our investigation and already gives a lot of information. First we can see that the main part of each image is a large letter: we can identify an ‘M’ and a ‘D’. These are enclosed within composite floral borders containing birds, animals and grotesques, as well as the arms of Castile and Aragon and the devices of the Spanish sovereigns Ferdinand and Isabella, the yoke and the bundle of arrows respectively.

Questions arise already and we start wondering what text these two initials introduced, from which manuscript(s) the images were excised, and what is their context. The catalogue description 2 suggests that the initial ‘M’ would have introduced Psalm 131 (the first psalm for Thursday Vespers) and the initial ‘D’ would have introduced Psalm 114 (the first psalm for Monday Vespers). This type of initial, “shaped and surrounded by densely populated foliage on highly burnished gold grounds, contained within frames inscribed with phrases from the accompanying text”, is, according to our curator Dr Stella Panayotova, “representative of Castilian illumination of the last quarter of the fifteen century which agrees with the internal evidence of the royal arms and devices.” The presence of the arms of Castile and Aragon as well as Ferdinand and Isabella’s devices does indeed give us a lot of information about the time of creation of these images. The two kingdoms of Castile and Aragon were united by this royal couple in 1479; in 1492, the pomegranate (not present here) was added to the royal arms to mark the conquest of Granada. We can therefore conclude that these images were created between 1479 and 1492.

Looking more carefully, we notice the strange layout of the borders. We can see that some of the animals are upside down and some of the drawings are incomplete. We are also aware that this sort of image with such large borders so closely attached to the large initials on all four sides is not commonly seen in illuminated manuscripts. Also, we have two large initials but no other text, so we start asking questions about what happened to these objects and how and why such images came to look the way they do today. At this point we have to start looking ‘beyond’ the image, at the materiality of the object: what is it made of and how can we explain the size and composition of the images?

Conservator’s approach

Last year MS 293a arrived at the conservation studio because it needed some treatment. The fragment was lined with cardboard which was acidic and causing tensions in the parchment. Both of these features were damaging the object.

MS 293a, backing cardboard
MS 293a under raking light

When MS 293a arrived at the conservation studio I followed the usual starting procedure of figuring out what I was dealing with. The catalogue description of the object gave me a good idea of the date of the illumination fragment and its iconography, but very little was written about its materiality.

Using raking light was the most effective observation method to understand the composition of the object. We can see the texture of the surface, giving information about the thickness of the paint layers and the way gold was applied. Raking light also highlights the presence of separate pieces of parchment. So not only is this a fragment from an illuminated manuscript, but it is an assemblage, a collage of several fragments. This explains the very complex completed image, acting as an individual painting.

MS 293a under raking light

Cutting illuminated manuscripts to create new ‘beautiful’ images was a fairly common practice in the 19th century and demonstrates the changing attitudes towards illuminations over time. Mid-19th century revival of interest in Gothic art led to the invasive exploitation of illuminated manuscripts where illuminations were cut and reused in a different context and format: MS 293a was assembled to stand as a painting. It is, as Stella Panayotova writes in the catalogue of the COLOUR exhibition, “a damage inflicted upon illuminated manuscripts, motivated paradoxically, by admiration for them as works of art”.

Backing removal

As mentioned before, the collage was supported by an acidic cardboard. It had been glued with animal glue and stuck firmly onto the board.

The illuminated cutting is painted on parchment which is made of animal skin and is both a very durable but also very reactive material. Parchment becomes stiff over time and reacts hugely to the relative humidity of the surrounding air so tensions can appear when the parchment is forced into a certain shape. My task was to remove the backing and mount the object to keep it safe and stable.

I had to remove the backing board layer by layer in order to reduce the risk of distorting the illumination which could disturb the paint layers. During the process the collage was laid onto a large piece of felt so that the illumination was not crushed. A thin layer of paper was found at the back of the collage and was probably the sheet of paper on which the pieces of the collage were originally adhered. We decided to leave it in place in case removing it would loosen the pieces. However, getting so close to the back of the illumination was intriguing so we looked at the object with transmitted light (now that it was fairly thin) and were able to make out large black Gothic letters. These letters are written on the back of the initial fragment. This was a magical moment and confirmed that the initial belonged to a very large manuscript.

MS 293a backing removal
MS 293a backing removal
MS 293a through transmitted light after backing removal

We had already so much information and could be fairly confident in attributing the illuminated initials to a Choir Psalter, written in Latin and originating from Avila in Spain in the late 15th century.

We also found out via observations under natural light and raking light that the collages were made of 8 fragments (MS293a) and 3 fragments (MS293b) respectively. Our curator was fairly confident in attributing the floral borders to the same illuminated manuscript as the initials. We could now go further in our understanding of the object and being able to reveal how the ‘artist’ who made the collage achieved the final composition. This is where our research scientist comes in.

Scientific approach

Collaboration with Dr Paolo Romano and Claudia Caliri from the LANDIS Laboratory in Catania (LNS-INFN and IBAM-CNR), allowed us to analyse MS 293a with a cutting-edge macro-XRF scanner, which they shipped here all the way from Italy! The spectral images obtained were interpreted by our research scientist and here is what they revealed:

The elemental map for iron (Fe-K) shows the presence of iron in various areas. The obvious place where we can see iron is in the gilded areas because iron is a constituent of Armenian bole, which would have been used as the ground layer for the application of gold leaf. However, we can also see what appear to be letters throughout the centre of the image. By flipping the image over (see image below) and adjusting its contrast we realise that these are indeed letters, written in iron-gall ink on the other side of this parchment page. Careful observation allows us to start reading the text hidden behind the collage.

MS 293b, elemental map for iron (Fe-K) flipped left-to-right

The false-colour elemental map for zinc, chromium and cobalt (in red, green and blue, respectively ) reveals the presence of elements, all of which are characteristic of ‘modern’ pigments. Combining this information with other analytical data, we can identify the presence of zinc white, cobalt blue, barium chromate and a chromium-based green, all of which were first manufactured in the first half of the 19th century. This information, together with the absence of any pigments manufactured after 1850, suggests that the collage was assembled, and the image retouched, probably in the 1840s, in line with the 19th-century practice of excising illuminations from manuscripts to create new art objects.

MS 293a, false-colour elemental map for zinc, chromium and cobalt
Conclusion

Collaboration between curator, scientist and conservator helped to retrace the origins and the story of these collages and to document them. These objects are new valuable objects, made of ancient valuable fragments. We won’t undo the collages because they document historic practice on top of being a new artwork. Besides, there is currently no parent manuscript so re-uniting the fragments is not possible – and if it was, digital methods could allow us to reunite fragments from all over the world by use of online digital tools, for example the IIIF (International Image Interoperability Framework). Separating the pieces could also damage the parchment and the paint layers, and having individual fragments without a specific place or use for them wouldn’t be appropriate.

Revealing the truths of an object is so important because we can’t undo what has been done for various reasons explained previously. However, we can document the object and share the information. One day, perhaps, through sharing information, we will find more related fragments that will feed into our understanding of the object itself and the historical practices involved and we may even be able to start reconstructing the illuminated manuscript that was once proudly standing in the Royal Monastery of St Thomas in Avila.

 

MS 197 (578 x 400 mm)

This cutting from our collection gives an idea of the scale of a Choir Plaster and how the fragments of the collage could have been laid out on a page. This is MS 197, from a 15th-century Italian Choir Book (see catalogued information’s here). We can see the large initial, the floral borders, the coat of arm and large black manuscript letters.

 

With special acknowledgement to Dr Paola Ricciardi, Fitzwilliam Museum’s Research Scientist, for her input with scientific research and imaging and for her help with co-writing this blog post.

 

 

Lantern Project in the Founder’s Entrance (Part 4)

Work on the Founder’s Entrance lantern is in full swing. The internal plaster conservation works were completed last month, along with the conservation cleaning.  And Tobit Curteis Associates have given us the below update on the conservation paint treatments they have been working on.

The scheme of decorative plasterwork and polychromy in the entrance hall is among the finest of its period in the country. It was conserved for the first time at the turn of the millennium at which point it was found that, although the surfaces were extremely dirty, having lived through the Industrial Revolution, the condition of the plaster and paint work was generally very good. Cleaning and conservation revealed the decoration in all its richness and had a huge effect on the appearance of the hall as visitors enter the museum. Some 17 years later, the conservation survey showed the condition still to be generally very good although there had been additional accumulation of dust and dirt as well as some minor flaking and loss resulting from unstable environmental conditions.

The aim of the current conservation project therefore is to record and document the condition of the decoration and to carry out limited stabilisation, cleaning and retouching. The team of conservators, working with Tobit Curteis Associates, has now been working on the conservation of the polychromy for three weeks and the work is progressing well. Most of the treatment carried out by Tobit’ team in 1999 and 2000 has remained stable and the areas of more recent damage have responded well to treatment. The planned relighting of the entrance hall will further improve its appearance so that visitors can again experience the decorative scheme much as the architect originally intended.

Tobit Curteis Associates

Work Placement – Manuscripts and Printed Books Conservation Studio

In the summer I spent four brilliant weeks with the conservation team in Manuscripts and Printed Books. Edward, Gwendoline and all the staff at the Fitzwilliam generously gave their time and knowledge to make my placement at the Museum enjoyable and an invaluable experience as part of the MA conservation course that I am studying at Camberwell College of Art. I completed a number of practical projects, including rebacking of cloth case bindings and the repair of architectural plans of the Founder’s Library.

Fitzwilliam Museum No 60, 1847 showing the Chimney Piece for the South Library

The architectural plans, mostly from 1847, were graphite and pen and ink on drafting paper – a transparent paper made by adding oil which, after many years, has degraded to make the drawings very fragile and brittle. This was a satisfying collection to work on as the drawings were taken off poor-quality backing paper, carefully flattened, and repaired with fine Japanese handmade paper. Finally, to make them easier to handle and visible on recto and verso, individual folders were made from Melinex®, an archival polyester film. For this I also got to learn to use some new pieces of equipment – the polyester sealing machine and ultra-sonic spot welder. With these I was able to make folders around the object, as you can easily seal as many sides around the enclosure as you need. It meant I could also get a wide enough border to prevent the corners of the drawings from being damaged in future. The ultra-sonic spot welder allows the old label to be displayed alongside the drawing in the same folder without the need for attachment to the Melinex®.

Polyester Sealing Machine

The Founder’s Library at the Fitzwilliam holds a wide variety of different bindings on rare examples of manuscripts and printed books. The cloth case binding rebacks I completed were for two volumes of the Arabian Nights Entertainment and an edition of Augustinus printed in 1490. Although all three bindings were nineteenth-century cloth case bindings, the damage and therefore the conservation treatment were each unique. I like the problem-solving element in taking a similar technique of creating a hollow-back binding to give durability and allow for the original spine to be put back in place, but taking different approaches depending on how he original structure was damaged and how that dictated access into the structure for repair with minimal disturbance to each binding. For instance, Volume II of the Arabian Nights had spilt endpapers making this an entry point to the spine whereas the endpaper joints in Volume I were in good condition so it was important to not damage these during treatment – access was through the spilt down the length of the cloth joint. The Augustinus had a whole piece of the spine detached and revealed a piece of printed paper used as a spine-lining that it was important to keep and protect in case it holds information worth future investigation.

Arabian Nights Entertainment Volume II, 4G17
Arabian Nights Entertainment Volume I, 4G16
Augustinus 1490, 6.K.11

Being in the studio meant that during the four weeks I was able to observe and learn from the diverse range of conservation treatments going on. Work on parchment was a new technique and material for me so I enjoyed being able to have a go at reproducing some historic and current repair processes. The area of printed books and manuscripts encompasses a range of different materials and techniques, with the additional consideration that bindings need to ‘work’ mechanically every time the volumes are consulted. I started a model example of a herringbone sewing: making this really helped me to understand how sewing on double cords works and locks each stitch in place for a very strong and flexible structure. As well as being ‘working’ objects, books and manuscripts are artefacts that need looking after and handling with respect. I think one of the factors in helping communicate this is the beautifully handcrafted bespoke cases and boxes made for items in the collection. The books need to fit exactly to protect them. The clam-shell box I made has double thickness on the walls making them very strong; lined with conservation board, they create a non-damaging environment within.

Parchment Repairs
Herringbone Sewing
Clam-shell Box

What made my placement particularly enjoyable was all the people who took the time to show me around and share their knowledge. I am grateful to have had the opportunity while in Cambridge to visit the wider conservation community there, from current students, Anna and Elisabeth, giving me a tour at the Hamilton Kerr Institute, to Jim and the team at the University Library showing me the many and varied conservation projects that they have going on, and to Bridget, Françoise and Claude at the Cambridge Consortium and Nicholas Bell at the Wren Library, Trinity College. I found the diversity of different projects being undertaken in all the conservation studios and treasures held in the collections fascinating.

Each of the departments at the Fitzwilliam also took time to show me the different projects that they have ongoing and their collections, from which a lot of exciting research is generated. It was good to see something of the day-to-day work of departments dealing with new acquisitions, items for loan and exhibition and challenges of storage and building constraints as well. I learnt a lot, and will continue to do so through my final year of study and beyond.

Finally I’d like to thank Edward Cheese and Gwendoline Lemée for making it an absolute pleasure to be in the conservation studio and taking the time to teach me many new skills. The experience went far too fast!

Preparing for ‘Flux’: Object Processing on a Large Scale

In the past year, the Applied Arts team has faced a monumental task: processing a group of 360 newly acquired pieces of Parian-ware (or Parian) porcelain, predominantly busts, in preparation for an upcoming exhibition. Most were dirty and many were separated from their original bases, which had become jumbled up. The scale of the project required that we think differently about how to care for the objects, finding an efficient way of processing them while respecting individual conservation needs.

The Glynn Collection of Parian-ware was acquired by the Fitzwilliam Museum in 2016 as part of the Acceptance in Lieu of Inheritance Tax scheme. Largely featuring busts of Classical characters and Victorian public figures, it provides an important insight into lives deemed worthy of commemoration in 19th-century England.

Acquiring such a significant collection opened up exciting possibilities for interpretation and display. The exhibition Flux (opens March 2018 in the Octagon gallery) is guest-curated by the artist and historian Matt Smith. As well as producing his own art, predominantly in clay, Matt has extensive experience of curating museum collections, often re-interpreting them from the view of an outsider. Flux will make use of his own unconventional Parian-ware (most fascinatingly produced in black Parian!) highlighting the Fitzwilliam’s historic collection and making it more relevant to a contemporary audience. The Flux display will accompany a major exhibition of studio pottery, Things of Beauty Growing, which will showcase ceramics sourced by the Yale Center for British Art, in New Haven, USA.

 

Parian-ware is named after the Greek Island Paros, known for its white statuary marble that was popular in the Classical world, which the porcelain imitates in appearance. Parian was a development of the biscuit (or bisque) porcelain used primarily by factories in France, such as Sèvres, to produce small-scale statue-like figures. This was developed further by porcelain manufacturers in Staffordshire, Britain, in the mid-19th century in order to give the surface a more reflective, marble-like finish. The slip-casting method, where liquid porcelain is poured into a detailed mould, allowed mass-production; making affordable, marble-like statues and busts available to middle-class Victorian homes. Parian was popularised by many British factories, right through to its decline in the early twentieth century. It was produced by many famous names such as Coalport, Wedgwood and Copeland. Factories competed with one another to obtain the finest Parian ‘recipe’. This has resulted in the many pieces within our collection having very different finishes, textures and weights. They vary greatly in density, porosity and colour: there are many shades of white and a few are tinted with coloured slips. Several busts are mounted on separate Parian bases, attached with threaded metal dowels. All these aspects need to be taken into account when treating each object.

The considerable size of the Glynn Parian-ware Collection made it necessary to develop a methodology that would allow streamlining the process of accessioning and conserving the porcelain in preparation for the Flux exhibition. The collection has occupied most of the available work surfaces in the department for much of the year, and clearing space was a priority. The first step required the combined effort of Departmental Technician Timothy Matthews and Research Assistant Helen Ritchie, who examined, photographed, measured and described the objects one by one, recording all information on a spreadsheet and eventually assigning each a museum accession number.

 

 

 

 

 

 

 

The condition was assessed by Penny Bendall, an independent ceramics conservator, who identified which objects required more complex conservation treatments, such as the reattachment of broken parts, removal of old repairs and re-mounting on bases. The vast majority just needed cleaning in order for them to be appreciated properly and to be made suitable for public display. The porcelain had more than likely been stored in different conditions and cared for in different ways by different owners. While many of the larger busts appeared to have been kept outside, their surface weathered and discoloured by accumulated dirt, smaller statues were far cleaner. Timothy Matthews and Assistant Conservator Flavia Ravaioli removed surface deposits using an enzyme-based detergent that activates in warm water. You will see from the photographs that a small amount of detergent was initially applied by brush and left on the objects’ surface for a few minutes to allow the enzymes to work. The detergent was then worked over the surface with the brush, taking care not to scratch the surface, until all the dirt had lifted. This was followed by thorough rinsing with specially-filtered water to remove all residues of the detergent. Finally, the porcelain was dried with soft cloths, then left in a warm place until completely dry.

When cleaning Parian-ware, we are very mindful of areas of restoration, the porosity of the surface, the presence of metal elements and old labels. When encountering a restored piece of Parian, we do nothing more than dust it with a dry brush, as using detergent and water could weaken or remove previous joins or restorations. A small handful of restored pieces were cleaned with acetone on small cotton wool swabs to allow more localised application.

Once clean, the objects were labelled with their accession number, photographed, and stored away to await display in the spring. So far 260 pieces have been completed. Only 100 more to go!

 

 

 

 

 

 

 

 

Timothy Matthews, Departmental Technician

Flavia Ravaioli, Assistant Conservator

 

 

 

Lantern Project in the Founder’s Entrance (Part 3)

Discoveries

Investigations into the lantern are well underway.  (Catch up with what has happened so far by reading Part 1 & 2.)

Specialist contractors Brown & Ralph have begun to look at the side windows of the lantern. After removing the glazing putty from one of the panes of glass, more information about the original intent has been revealed.

Original pane of glass removed

Each pane has a central section of etching, with a clear border around the edges. Over the years, as repairs have been done and panes replaced, the putty and paint lines have crept further inwards, making the clear border not visible.

Red dotted line showing original line

The glass will be removed and cleaned. And, as the glass is reset, the putty line will be restored so that the clear border will be visible again. Looking at the windows as a whole, it is possible to tell which panes have been replaced.  The ones with a rose tint are original.  As part of this project, we intend to replace the newer non-tinted glass with rose-tinted etched glass in order to return to the original aesthetic.

View of side windows showing difference between old rose-tinted panes and the later non-tinted panes

Keep an eye on the blog – we will keep you updated as the project progresses.

 

Uncovering Treasures: Conservation of Works on Paper in the Sir Ivor and Lady Batchelor Collection

In 2015 the Fitzwilliam received an exceptional bequest of around 250 works on paper, paintings and applied arts items, the collection of Sir Ivor and Lady Batchelor. Since then, paper conservators and technicians at the Fitzwilliam have undertaken a project to conserve the drawings, watercolours and prints from the gift – documenting, treating and preparing them for archival storage and future display

The Collection

Professor Sir Ivor Batchelor (1916-2015) was an eminent psychiatrist, academic and advisor to the National Health Service. He developed a love of art as a boy and began a lifetime of amateur collecting, later sharing his passion with his wife Honor.1 They regularly made gifts to the Fitzwilliam throughout the 1990’s, notably enhancing the museum’s collection of drawings by James Ward. The 2015 bequest features predominantly British C19th and C20th drawings, prints and watercolours. Favoured artists include David Cox, Frank Brangwyn, Edwin Henry Landseer, David Wilkie, Muirhead Bone, William Orpen and Walter Sickert, as well as earlier works by James Ward, Heneage Finch, Thomas Rowlandson and others. It was the distinction of great draftsmanship, coupled with affordability, which dictated most of their purchases.

The Conservation Project

The works arrived at the museum in a variety of mounting and framing styles.  The condition of the works varied: many were in reasonably good condition, while others had been visibly affected by factors such as light, humidity and contact with degraded mounting and framing materials. Some works (such as the drawings by Walter Sickert) are in themselves made of poor quality papers which show the effects of age much more quickly than better quality artist’s papers.2

Technicians in the Department of Paintings, Drawings and Prints unframed the works, photographing the frames and documenting inscriptions and labels on the frame backboards. The works were placed in folders and stored in archival boxes ready for accessioning by curators.3 Cataloguing in this case is being carried out alongside the conservation project – the process of unframing, examination and treatment sometimes reveals new information about the work, as can be seen in some of the examples discussed below.

Each work is thoroughly examined, photographed and documented by conservators before any treatments are undertaken (as well as during treatment). Many items in the Batchelor collection have only required the removal of old hinges and mounts, pressing and re-mounting.4 Others however have required more interventive processes, such as backing removal, stain reduction, washing and various types of repair.

Discovering a new drawing
David Cox The Foot of the Cliff, graphite pencil on paper (232 x 155mm) PD.75-2015

Removing this graphite drawing by David Cox (1783-1859) from its acidic backboard revealed another image on the reverse of the sheet – a roughly executed watercolour of a rocky landscape and some figures in pencil – probably dating from around the same time, as this page previously formed part of a sketchbook. Old adhesive was removed, the sheet was pressed and the work was mounted in a ‘double-sided mount’ so both sides of the paper can be viewed and also protected.5

Exposing the verso drawing during the backing removal process
Verso of drawing after treatment
Doodles and marginalia
Frank Brangwyn, A Rhinoceros, a study for the British Empire panels, graphite pencil and red ink on paper (227 x 267mm). PD.60-2015. The drawing in its old window mount, with edges of the drawing covered.

This studio drawing by Frank Brangwyn (1867-1956) was soiled and creased with some prominent stains caused by the old acidic window mount. The window also partly covered the artist’s inscription and completely obscured other interesting drawings around the edges of the paper. It was decided to remount the work showing the entire sheet. Due to the sensitive nature of the red ink, cleaning and stain reduction could only be done ‘locally’. The newly mounted sheet looks much less cramped and gives us greater insight into the way the artist worked.

Showing the edges of the work after treatment
Out-foxing the Foxing
John, Gwen (1876-1939), An adolescent girl, standing in a landscape, charcoal on pale buff paper, (232 x 155 mm). PD.207-2015. After treatment.

The chalk media of this drawing by Gwen John (1876-1939) was fresh and unfixed. However, the machine-made paper was poor-quality and severely discoloured overall. There were several disfiguring large brown stains, or ‘foxing spots’ scattered across the image area6  The spots were treated with water and alcohol followed by careful bleaching and a final rinsing. By using a ‘suction point’, the stain removal process was carefully controlled – the spots no longer detract from the delicately drawn image.

Detail of foxing spots
Removing foxing spots using the suction point
Emerging from the Darkness
William Orpen, Self Portrait graphite pencil on paper. (191 x 153mm). PD.147-2015. After treatment.

The buff-coloured sketchbook paper used by William Orpen (1878-1931) for this sketch was of an inherently poor quality and had become acidic, dark and brittle. The sheet was undulating and distorted from old self-adhesive tape holding it in place. After removal from the mount and testing of the media, the drawing was given several washes in cool then warm de-ionized water to release the acids and impurities and re-invigorate the paper. It was then lined with a carefully chosen light-weight Japanese paper and starch paste to provide the paper with extra strength and support for the future.

Immersion washing in warm water
The Outcome

Whether the conservation work is preventive or interventive, the end result is gratifying – the treated works are now stabilized and ready to be accessed for viewing, display or loan. They are now protected by their new museum-quality acid-free mounts and are stored safely in high-quality Solander boxes.7 After treatment, high-resolution digital photographs are taken before the works are returned to the climate controlled Prints and Drawings store. The Batchelor Collection conservation project for works on paper is ongoing and there will be an exhibition of selected works from the collection at the Fitzwilliam in 2018.

Completed mounted works in their Solander box

 

All images © The Fitzwilliam Museum, Cambridge unless otherwise credited.

With thanks to Richard Farleigh, Gwendoline Lemee and Jane Munro for their assistance.

Lantern Project in the Founder’s Entrance (Part 2)

Atlantes and lantern side windows viewed from scaffold platform
Protection during installation of scaffolding

The installation of scaffolding took several weeks. During this time, there was a great awareness of the potential risk to the historic interiors and the collections in surrounding galleries.  There were several methods of protection in place, to minimise risk from physical damage (e.g. knocks, scratches), as well as dust.

Foam and plywood were used to protect the historic mosaic floor. Sculptures which could not be moved were boxed in.

Nearby objects were protected from potential knocking and additional dust fall.
During the scaffold construction, the balustrade, bannisters and floor were boarded. Boards underneath scaffold legs ensured the additional load to the floor was spread. The scaffolding was cleaned before coming into the building, and clean wood was used. There was an increased risk of dust ingress as the front door would have to be left open while materials were moved into the building, so additional dust protection was in place; plastic sheeting proved invaluable to minimise dust movement to surrounding galleries.
Up close
Scaffold platform aptly nicknamed ”The Ballroom”

Now the scaffolding is up, survey work has begun and it provides a rare opportunity to get up close and personal with the lantern interior.  Not only do we need to establish the extent of any deterioration or damage to the building and its decorative interiors, but also if we can understand the causes.

For example, staining in the dust below the side windows indicates that there has been condensation or water ingress. Closer inspection of the internal timber reveals that there is a condensation tray at the base of the lantern side windows. This design originally allows for collected condensation to flow through an outlet pipe to the outside.  It may be that the pipes have been blocked by insects, causing the tray to overflow.  To stop this happening in the future, we need to confirm the cause and either make modifications to the design or ensure changes to the maintenance of the current pipework.

Interior condensation tray with pipe leading outside
Exterior pipes for condensation pipes

We are still at the early stages of the project, and so survey of the plasterwork and internal decoration are ongoing.

We shall keep you updated as the project progresses – watch this space!

It’s on my Christmas list: The Hirox 3 D Digital Microscope

Earlier in the year a small group of Fitzwilliam conservators were given  fascinating insight into the new and latest Hirox 3D Digital Microscope, PC Edition (RH-2000). A pretty sophisticated bit of ‘non destructive analytical kit’ by any comparison. Neat and tidy, with an impressive ability to process complex data fast.

As is often the case in conservation this technology has been developed for and embraced by other industries requiring ‘close scrutiny and exacting quality control’ such as precision engineering, electronics and other fast emerging fields such as nanotechnology. So, conservation sitting on these rather better funded coattails by way of mutual benefit, is no bad thing. Thank you, Formula One.

On the day, the brothers Alessandro and Marco Brecciaroli (representing Hirox) smoothly and in a charming way, guided us through the system. All too often in life it is difficult to make the full and appropriate use of a piece of equipment until one knows ‘just what it may be capable of’ and believe you me, Hirox is no slouch!

We were keen to see just how such a clever microscope could help in the field of Conservation. Could it extend the parameters of observation and perhaps more specifically, enhance our understanding. Quite possibly, and as such, this was an opportunity too good to miss.

Several of us brought museum objects with us on the day, mostly small and necessarily portable by way of putting Hirox through its paces – real objects under real scrutiny.

These included an early stained glass fragment, a painted swatch of powdery blue pigment, an intriguing small Egyptian coffin, a pre prepared pigment cross section cast in resin and a surface detail from a rare 19th century French watercolour painting.

Early stained glass fragment

      Post medieval stained glass panel (4230a Department of Applied Arts)
     A studio photograph using a conventional camera

Hirox got up close and personal and the revelations, to say the very least, were impressive.

 

In the detail above, courtesy of Hirox, we see the black tracing line,  subsequent coating of blue enamel and the surface disruption to the glass below. 

The glass surface is mildly scratched, it contains inclusions of sand (most probably silicate not fully melted during the original glass making process) and has a number of small ‘alluring air bubbles’, held captive since the middle of the seventeenth century!

The decorative element is now cracked and there are several small losses. As such, this particular artefact is somewhat at risk from further flaking.

Key features of Hirox

-Wonderful graphic quality, breath-taking magnification and the ability to capture and merge multiple images and/or create videos. And if that were not enough Hirox can be fitted with an endoscope enabling the investigation inside of an object.

-Uncompromising picture sharpness and reduced Digital Noise by way of ‘smart focusing’ and a camera that boasts the capacity to take somewhere between 50-100 frames per second, all at high resolution (1920 x 1200 pixel).

-Lighting is versatile, delivered by Light Emitting Diodes (LEDs) at a colour temperature of 5700 Kelvin. Various options include: Reflected, Transmitted, Bright Field / Dark Field and Polarization. Lighting with an Ultra Violet spectral range of 200-400 nanometres is also available if required. It would be prudent to check on both the emitted and cumulative light levels in particular and with regard any potentially light sensitive items.

-A broad range of high quality lenses are available anywhere from 1:1 to a staggering 10,000 x and numerous variant thereof. The changing of lenses appeared quick and easy by way of a bayonet fitting.

 

What soon became clear is that the examination of a small sample size and/or object was somewhat easier. For larger items one would require more careful planning and adequate space in order to engage the services of a bespoke and importantly ‘stable jig’.

Another option includes the use of a portable contact hand held lens.

Painted swatch of powdery blue pigment

Something as simple as the inclusion of a scale, seen here below in ‘microns’, is especially useful whether making a passing assessment or perhaps more so, by way of any future comparison.

The above image illustrates a powdery blue pigment part coated with a white waxy Cyclododecane1 consolidant –  in this case applied via an aerosol and now part sublimated  (evaporated).

Small Egyptian coffin

c. 600 BC / before the Common Era

The coffin surface is heavily deteriorated leaving very little of the original decoration and as such, one is left searching for clues. Hirox affords a different viewpoint and to some extent ‘a journey into the unknown’.

A small Egyptian wooden Coffin (E.43. 1907 Department of Antiquities)
44 cm (L), 13 cm (W), 14 cm (D)

Video footage across the coffin surface

The pigment trace seen in this short video is Egyptian Blue2. The remnant is trapped in one of the cracks of the coffin’s surface and although not wholly surprising it does indicate that the entire ‘wig decoration’ would have originally been painted in blue. This sort of information not only helps in our understanding of the object but it also allows for a far more accurate interpretation.

Pigment cross section

An example of a ‘stitched image’ captured by Hirox

Calcium ground      Egyptian Blue pigment           Varnish layer

Cross section of a paint sample containing Egyptian Blue (in this case a minute pigment sample was cast in resin and polished, prior to viewing).

19th century French watercolour

France, Normandy to be precise. The handy work of just who ?

This rare artwork will be on display at the Fitzwilliam Museum in the autumn of 2017 in what promises to be an exquisite show. The maker will be revealed and much more besides.

A gum glaze over watercolour         Surface abrasion

A close surface detail of a watercolour painting showing assorted fingerprints and other interesting information

3 dimensional modelling

Art meets science and maths, ooh and some pretty impressive graphics.

Real time measurements including length, angle and the surface area can be captured detailing the terrain and presented various styles. For obvious reasons, this sort of data could prove invaluable by way of comparison should the need arise, post loan or perhaps, assisting with an on going object ‘condition appraisal’.

3D Modelling of the powdery blue pigment part surface coated with Cyclododecane wax (see the earlier image of the same by way of comparison)

Like so many things in life, in order to capitalize on any investment (prices start from around £60,000 at the time of writing) one would have to give Hirox time and with that time one could reap bountiful rewards.

As such, I remain hopeful this Christmas!

 

For more information visit:

www.hirox.com

Alex Brecciaroli, Sales & Technical UK

alex@sharedlabseurope.com

www.sharedlabseurope.com

 

Thanks go to Alessandro and Marco Brecciaroli for their captivating  introduction to this impressive piece of equipment and also, to my many ‘kind and resourceful’ museum colleagues.