Annual Inspection of the Thornham Parva Retable

The Thornham Parva Retable. © C. Titmus. With many thanks to the wardens of St Mary’s Church, Thornham Parva.

The Thornham Parva Retable was made circa 1330-1340, and is one of a very small number of such objects known to survive in Britain. It is a remarkable and important extant medieval English religious painting and sits behind the altar at the east end of the chancel in the tiny church of St Mary, Thornham Parva, Suffolk. In February 2019 a team of staff, students and interns from the Hamilton Kerr Institute drove to the church to conduct an inspection of the Retable, a duty performed annually since its extensive conservation treatment at the Institute almost 20 years ago.¹ While we were in the area we paid visits to two other churches, Yaxley and Eye, to see their rood screens; a genre of late medieval decorative painted church furniture with over 500 survivals in East Anglia.

The church of St Mary, Thornham Parva. © Hamilton Kerr Institute

The Thornham Parva Retable

The Thornham Parva Retable is a horizontal panel some 3.9m long and 1.1m high, divided with columns into 9 sections which depict respectively, from left to right, Saints Dominic, Catherine, John the Baptist and Peter, the Crucifixion with the Virgin and St John the Evangelist, and Saints Paul, Edmund, Margaret and Peter Martyr. A Retable is an altarpiece; a panel decorated with devotional images that would have been positioned behind the altar and formed the backdrop to the liturgy. This Retable is thought to have been commissioned by the Dominican Priory at Thetford, Norfolk, and the depicted saints point to a Dominican patron. The Retable’s considerable size and quality are indicators of origins in a large and wealthy religious house. Stylistic similarities have been noted between the images on the Retable and designs on medieval glass fragments excavated from Thetford Priory ruins. The Cluny Frontal (Musée National du Moyen Age, Paris) has been identified as the companion piece, showing scenes from the life of the Virgin, which would have been positioned at the front of the altar table. The same craftsmen collaborated on both pieces.

Thornham Parva
The Retable inside the church, viewed through the Medieval rood screen. © L. Wrapson.

The Retable is constructed from oak, and its straight grain indicates that it was imported from the Baltic, which is common in panel paintings in England from the Middle Ages to the Early Modern period. It also had a frame originally that would have been affixed to the support prior to painting and decoration. The original frame on the Cluny Frontal gives some indication of what its appearance might have been here. The panel is has a ground of chalk bound in animal glue, and analysis has suggested that the chalk may well have geological origins near Thetford. The design for the painting is drawn out onto the chalk layer, and some of this drawing was executed in the bright red pigment vermilion, which is unusual. Next, a layer of lead white in oil was applied. The sumptuous background decoration, comprising squares of gilded ‘tin-relief’ designs, would have been applied before the figures were painted. The name ‘tin-relief’ derives from the technique for this form of decoration. The reliefs are made of putty containing a mixture of pigments in resin and oil, which was pressed into a mould lined with tin-foil as a release layer. A variety of moulds were used here. This decorative technique is particularly interesting because it was to feature prominently in the later medieval rood screens of East Anglian churches. The figures are painted in a bright array of pigments including lead white, blue azurite, red and yellow earth pigments and copper-based greens. These were also mixed and blended to give other colours and tones. A greater range of colours and effects was created by glazing over the top with transparent pigments like red lake and the copper green pigment verdigris.

Detail of lamb motif in tin relief. © Hamilton Kerr Intitute

Rediscovered in 1927 in Thornham Hall, where it existed in three sections, the Retable was installed in St Mary’s and throughout the 20th century was transferred to several places in the country at various times, escaping war, travelling to an exhibition in France, and receiving intermittent conservation treatments to secure the paint and re-gild the background. It came to the HKI between 1996 and 2001, where, with funding support from the National Heritage Memorial Fund, English Heritage, World Monuments Fund and Samuel H Kress Foundation, it received full conservation, including consolidation (re-adhesion of flaking paint and ground), cleaning and removal of multiple and thick layers of overpaint, discoloured resin varnishes and previous wax-resin adhesives. Extensive research and technical analysis were carried out, including dendrochronology, X-ray and pigment analysis, and reconstructions to further explore certain aspects of the technique. As a result of the treatment, the majority of the paint represents the original medieval scheme and, despite the areas of damage and paint loss incurred from iconoclasm and neglect, the painting is in exceptional condition for its age. The conservation also involved monitoring and improvement of the environmental conditions within the church and provision of a protective enclosure for the Retable, and the work continues in the form of an annual inspection. These are all examples of what is known as preventive conservation.

Preventive conservation and the Thornham Parva Retable

Preventive conservation is a branch of conservation and preservation that involves creating and implementing policies to passively ensure the longevity of cultural heritage. The Canadian Conservation Institute (CCI) has identified ten “Agents of Deterioration” that act as an outline for what might harm cultural heritage.² Therefore, preventive conservation is concerned with environmental monitoring, documentation, integrated pest management, proper handling policies, implementation of security measures, and protection from fire, water, pollution, and too much light. Some of the actions a conservator might take to mitigate the potential harm include periodic condition assessment of objects and their environment to keep a record of changes, and to be alert of any changes that might be a detriment to the preservation of a work so they may be mitigated. All of this work ensures the long-term protection of works of art, including pieces like the Thornham Parva Retable.

With this in mind, students and interns led by Dr Lucy Wrapson, all from the HKI, set out to Thornham Parva to do a yearly condition check of the Retable and lightly clean its surrounds.  The Retable is set on the altar in a specially-made case, which protects the piece primarily from dust, changes in temperature and relative humidity, and possible theft or vandalism. The case was integrated into the structure of the nave so it was as unobtrusive as possible and still allowed the congregation to us it as it was intended.  As part of our inspection, we were able to lower the glass in front of the Retable and get a close look using flashlights and head loupes. This way, we were able to look for any flaking or other damage that might have occurred over the course of the last year.  Fortunately, there was no change in the paint and ground layers, except a bit of dust build up, which we very gently removed with a soft brush. Cobwebs around the case were also vacuumed up, as well as some salt efflorescence that perennially emerges between the floor and the wood panelling at the bottom of the case on the north side. While the source of this salt is not clear, it is important it is monitored and documented, as a change in the pattern can be an indication of something amiss with the building envelope. We also cleaned the inner and outer faces of the glass of dust and smears, so that the colours and details of the paintings can be fully appreciated.

Dusting the case with the glass partly lowered. © Hamilton Kerr Institute.
Salt deposit on the floor at the foot of the frontal. © Hamilton Kerr Institute.
Carefully cleaning the outer and inner faces of the glass, half-lowered, which required getting into some interesting positions! © Hamilton Kerr Institute.

The stable condition of the painted Retable speaks to what passive measures can do for the preservation of cultural heritage. For example, the red lake pigments are still very bright in the painting, which is very rare for an object of this age. These bright colours possibly suggest that the Retable was protected from bright light, which would have faded this fugitive pigment. Similarly, the wooden panels have been largely spared from damage by wood-boring insects, so they are still structurally sound. This special object was clearly valued by the community that had it made, and its stewards over many hundreds of years, including the current Thornham Parva community. The conservators at the HKI, in conjunction with the current church community, are able to use the principles of modern preventive conservation to continue to maintain the Retable for future generations.

Two Suffolk medieval rood screens

While we were in the area we had the opportunity to visit the rood screens in the churches of the nearby village of Yaxley, and the town of Eye. ‘Rood screen’ is the generic term that refers to the composite divisional structure that separated the chancel from the nave in a medieval church, and East Anglia contains the densest concentration of this type of object Europe-wide. Most screens that survive were constructed between the early 14th and mid-16th centuries, and they were known by the names rood loft, candlebeam, perke, and a host of other interchangeable terms. They were composite structures generally consisting of the dado (the lower part, bearing images of saints – this is usually the only part that survives in the church) and an upper traceried part, surmounted by a beam bearing the rood group (a wooden cross and figures of the Virgin and St John the Evangelist). The saints and angels depicted on screens acted as intercessors through whom the prayers of the local communities reached God. Screens were the work of multiple workshops that included carpenters, painters and sculptors, some of whom engaged in multiple crafts. They also would often have been fabricated piecemeal, with multiple donations, usually in the form of will bequests, for the construction or decoration of separate parts of the structure – for example, an individual or a local guild might dedicate a sum in their will towards the painting of their name saints. Many screens have been lost or severely defaced in bouts of iconoclasm following the Protestant Reformation and during the English Civil War. Of those that do survive, the work of certain craftsmen or workshops has been identified on a number of screens, which was a focus of Dr Lucy Wrapson’s PhD.³ Click here to view the blog post about the conservation of the rood screen in St Matthew’s church, Ipswich, in 2016.

St Mary’s church in Yaxley is a mainly 15th-century structure with a magnificent porch featuring flint flushwork, and a roof with carved angels and other figures. There is also a doom painting above the chancel arch. There is beautiful gilded tin relief to be seen on this screen, including a charming little face with a sticking-out tongue, and the saints’ garments are decorated with intricate brocade patterns. We looked closely at the carving and carpentry, which features intricate designs and is the output of the same group of craftsmen who worked on the screen at nearby Eye.

The rood screen in St Mary’s church, Yaxley. © L. Wrapson.
Detail of St Mary Magdalene on the rood screen at Yaxley. © L. Wrapson.
Detail of face with tongue sticking out in tin-relief background at Yaxley. © Hamilton Kerr Institute.

As Eye was a wealthy wool town in medieval times, the church here was notably large and grand. In this screen, the dado is medieval and most of the rood loft and beam with rood group is the early 20th-century work of Ninian Comper. The painted saints on this screen are very different in style to those on the Yaxley screen, being much more generic and less refined (but still charming). Here the saints were generally arranged male-female alternately, whereas those on the Yaxley screen were mostly female. The tin relief designs in the background here are much simpler than at Eye. Lucy highlighted the similarities of the carving and tracery designs on the spandrels and in the lower dado with the Yaxley screen and pointed to the remains of a dedicatory inscription on the loft.

The rood screen in the church of St Peter and St Paul, Eye. © L. Wrapson.
Detail of St Agnes on the rood screen at Eye. © L. Wrapson.

Preventive conservation measures are important for the protection of rood screens, although sadly many exist in churches with uncontrollable humidity, temperature and light levels and are deteriorating as a result and suffer damage from insects such as deathwatch beetle. The visits we made today were an insight into the treasures that survive hidden in East Anglia’s churches, and the story of the Thornham Parva Retable exemplifies what is possible with the enthusiasm, support and collaboration of people with diverse interests, knowledge and professional skills, and what might be achieved for rood screens in the future.

Katharine Waldron and Ellen Nigro, 1st year Post-Graduate Interns (2018-2020)


1. Massing, A., ed., The Thornham Parva Retable. Technique, Conservation and Context of an English Medieval Painting (Hamilton Kerr Institute, University of Cambridge and Harvey Miller Publishers, 2003).

2. Canadian Conservation Institute, ‘Agents of Deterioration’. Retrieved from, February 2019.

3. Wrapson, L., ‘Patterns of Production: a technical art historical study of East Anglia’s late medieval screens’ (PhD this, University of Cambridge, 2013).

About the Authors:

Ellen Nigro graduated from the University of Delaware in 2013 with a B.A. in Art Conservation and Art History. After gaining internship experience through projects at the Freer and Sackler Galleries, Shelburne Museum, Villanova University, and the Chrysler Museum, she entered the Winterthur/University of Delaware Program in Art Conservation (WUDPAC). Her projects in the program included developing a consolidation strategy for a matte, underbound, 19th-century Thai panel painting, and completing a technical study on it. She earned her M.S. from WUDPAC in 2018 after her third-year internship at the Royal Picture Gallery Mauritshuis as the Fulbright-American Friends of the Mauritshuis Intern.

To contact Ellen:

After completing a BA in History of Art at the University of Warwick, Katharine graduated from The Courtauld Institute of Art in 2018 with a Postgraduate Diploma in the Conservation of Easel Paintings. One of her projects involved the conservation and technical research of a modified 17th-century harpsichord lid, which led to her third-year dissertation project on historical copper green glazes. She has worked for Katherine Ara Ltd. and as an intern with the National Trust, the House of Lords, the National Maritime Museum, the V&A, and the RCE in the Netherlands as a Zibby Garnett scholar. Among her current projects at the HKI, Katharine is involved with research into the pigments and techniques of church polychromy in East Anglia.

To contact Katharine:

Rood Screen Conservation at St Matthew’s, Ipswich

Six panels forming part of a rood screen housed in the medieval church of St Matthew’s in Ipswich, Suffolk, were the subject of a week-long in-situ in September 2016 by Christine Braybrook and Sarah Bayliss.

Medieval rood and parclose screens are decorative partitions that separate the chancel from the nave in a church, and were usually decorated with painted panels depicting saints or donors. Few of these screens survived the destruction and damage from iconoclasm during the Reformation and Civil War in England, but in East Anglia there are a significant number of them left which allows meaningful study and comparison of their construction and painting. This research was the focus of Dr Lucy Wrapson’s PhD thesis, Patterns of production: a technical art historical study of East Anglia’s late medieval screens (2013, University of Cambridge). The in-situ project was a direct result of this body of work as it was noted upon examination that the St Matthew’s rood screen was in need of consolidation in order to stabilise flaking and vulnerable paint.

(Click to enlarge photos)

Like many medieval churches, St Matthew’s has had several phases of building and re-building. The south arcade (where the rood screen is present) is late 14th century, the chancel, north arcade and west tower 15th century and the aisles and part of the tower 19th century. This medieval building continues to function as a modern day church and was warm with excellent tea making facilities – so top marks from the conservators, St Matthew’s!

The St Matthew Rood Screen

The six painted panels of the St Matthew’s rood screen depict four bishop saints and one male and one female group of donors (fig. 3). The panels have suffered a lot of damage during their history including significant iconoclasm to the faces of the bishops, accidental damage and ‘refitting’ to more modern tastes. The six panels are all that remains of the original rood screen as they have been set into a 19th-century screen, and it is probable that it was during this intervention that the colourful backgrounds were scrapped down to the plain wood. However, it is possible to see the shape of the original upper and lower dado tracery from the ghost shapes of the gilding on the paintings (fig. 4). A comparison of these tracery shapes with other parclose and rood screens (notably at Southwold and Woodbridge) ascribes a date range of c.1448-70 for the St Matthew panels.

Fig 3. The St Matthew’s rood screen, before treatment. The order of the panels from left to right show (possibly) St Thomas Becket, unknown bishop saint, unknown bishop saint, (possibly) St Erasmus, group of male donors, group of female donors. (© Bayliss)

Unfortunately, the four bishop saints have few iconographical features to allow them to be easily identified. It has previously been suggested by A. Baker that the first and fourth saint in the sequence are St Thomas Becket and St Erasmus respectively. This is based on the vehemence with which the first panel has been defaced (literally and metaphorically), as St Thomas Becket was a particularly hated figure during the Reformation (fig. 13), and the windlass held by the fourth saint is the attribute of St Erasmus. As the panels have been removed from their original structure and context, it is unknown whether the panels would always have been set out in this sequence.

Fig 4. Detail of the current wooden tracery and underneath the ghost of the original tracery shapes from the remains of the gilding. This photo shows the gilding on the right with the varnish removed, and the gilding on the left with the old varnish remaining. (© Bayliss)

Condition and Treatment of the Rood Screen

Upon examination, it was clear that some of the paintings had vulnerable raised and tenting paint, which could easily be knocked off and lost forever. They were also obscured by surface dirt and an old and very discoloured brown varnish, which had the effect of camouflaging the figures against the wooden backgrounds and dimming the original gold and bright pigments.

The first stage was to consolidate and secure the flaking paint, an important step in helping these rare paintings to survive as it limits further paint loss from these already damaged paintings (fig. 5). The paintings were then surface cleaned using Blitzfix™ sponges soaked in deionised water, pH adjusted with ammonia to pH 8-9 (fig. 6). While a lot of dirt was removed from the surface of the paintings, there was little aesthetic improvement.

(Click to enlarge photos)

Next, tests were undertaken to remove the dark and disfiguring varnish. Rood screens often have multiple layers of aged resin and/or oil varnishes, making varnish removal on-site extremely challenging, away from the comforts of a fully equipped conservation studio. However, in this case a small miracle occurred and the varnish was readily soluble using free solvents, revealing the beautifully preserved original paint film and gilding (fig. 7-9). After much rejoicing, we begun what turned into one of the most satisfying cleans I’ve ever done. The thick, brown varnish was removed, revealing the figures in all their remaining glory. The change was stunning as the gold regained its lustre and the pure colours of the robes were revealed. But what I enjoyed the most was seeing the faces again, no longer a dull shadow of the wood, but standing out against the background with their black drawn features and pale skin.

(Click to enlarge photos)

The varnish removal also allowed us to see more clearly aspects of the panels’ making. In some areas the underdrawing, which had previously been only visible in the IRR photographs of the paintings, became apparent through the paint and gilding. We were also able to find remnants of the coloured backgrounds (fig. 11). It was previously thought that, like many paintings of this time, the backgrounds would have been alternating red and green, but in actual fact all of the backgrounds were green. It also became evident that the robes of the bishop saints had been gilded completely and the decoration painted on top of the gold, rather than the artist/s leaving a reserve to reduce the amount of gold used (fig. 12).

(Click to enlarge photos)

Once cleaned, the paintings were brush varnished with Paraloid B72, a stable, synthetic varnish which will not discolour anywhere near as much, nor as quickly as the previously applied natural varnish!

(Click to enlarge photos)
Fig. 16 The rood screen after treatment. (© Bayliss)

This project was immensely satisfying and it was also wonderful to hear the surprise of members of the church at how changed their paintings looked. It was also a very pleasing change for us, as in-situ work tends to be more concerned with stabilising paintings and frames rather than transforming them. So to leave behind the rood screen glimmering gently, rather than lost in the shadows, was certainly an excellent end to the week.

Sarah Bayliss, 2nd year Post-Graduate Intern (2015-2017)

About the Author:

Ms Sarah Bayliss is a graduate of the Post-graduate Diploma in the Conservation of Easel Paintings at The Courtauld Institute in London. She also has a Master of Chemistry from the University of East Anglia in Norwich, UK.

To contact Sarah Bayliss:

Eton College In-Situ

In late May 2016, fellow Post-Graduate Intern Camille Polkownik, Director Rupert Featherstone, and I worked on a number of paintings at Our Lady of Sorrows Chapel on the campus of Eton College, located near Windsor Castle.

Our Lady of Sorrows Chapel at Eton College (© Polkownik)

Over the course of three days, we treated eight paintings on site. While this in-situ project involved a number of procedures routinely carried out under such circumstances, including consolidation, surface cleaning, minor tear repair, minor filling and retouching, varnishing, and conservation-standard re-framing, we encountered a number of slightly unusual challenges that warrant mention.

Two of the paintings, upon closer inspection, were found to consist of paper adhered to canvas, which was in turn attached to keyable stretchers. These paintings appeared to have been executed in an oil-type medium and had darkened coatings, possibly tinted to make the paintings look older. Extra caution was taken during surface cleaning as a result of the potential sensitivity of the paper supports to water. After some testing, the solution settled upon was to use a lightly dampened “Blitz-Fix” sponge and dry the surface immediately with Kimwipes (acid-free tissues).

Additionally, while saliva or deionized water at pH 7 or 8 on cotton swabs would generally suffice for surface cleaning varnished paintings, two paintings – one varnished, one unvarnished – were found to warrant the use of a cleaning solution with a low percentage of an added chelator on cotton swabs due to the significant amount of tenacious grime present. These paintings, previously appearing rather dull and grey, underwent dramatic visual improvements after surface cleaning. Re-varnishing these paintings was also necessary and provided aesthetic benefits.

For health and safety reasons, the choice of which varnish to use while on an in-situ can oftentimes be limited to the synthetic varnish requiring the least harmful solvent. Fortunately, we were able to time the progress of our treatments such that we could varnish at the end of the second day prior to leaving the building, preventing human exposure to solvent vapours. This allowed us to use Paraloid® B72, for example, which we found particularly beneficial to employ on paintings with uneven gloss.

Framing and hanging presented a few challenges as well. We needed to consider several special modifications when re-framing the paintings, including enlarging the rebate of one of the free-standing frames, since the painting didn’t quite fit. The college staff also took the opportunity to modernise the hanging hardware.

Polkownik cleaning a frame (© Rayner)

It was a privilege to participate in this project at Eton – not just because we were treated to Eton College behind-the-scenes, or because we managed to fit in a few strolls in the evenings to see the incredible number of swans on the river! It was a pleasure to work in such a lovely space, and it was a valuable learning experience to encounter such a range of conservation issues on site.

Many thanks to the welcoming and supportive staff at Eton College for inviting us to work on site. We hope that the congregation of Our Lady of Sorrows appreciates the aesthetic improvement of the paintings and that our efforts have added to an enjoyable experience of the chapel.

Kari Rayner – 1st year Post Graduate Intern at the Hamilton Kerr Institute

Ms Kari Rayner graduated with a Master of Arts in Art History and gained an Advanced Certificate in Art Conservation from New York University, USA. She also has a Bachelor of Arts in Art History, Art Theory and Practice from Northwestern University, USA. During her graduate studies, Kari interned at the Wallraf-Richartz-Museum in Cologne and worked at Modern Art Conservation in New York, NY. Her final-year internship was undertaken at the National Gallery of Art in Washington, D.C., and she will be returning to the NGA in fall 2016 to begin an Advanced Fellowship in Paintings Conservation.

To contact Kari Rayner:

In-situ at Deene Park, Northamptonshire

Back view of Deene Park at the end of day. (© Polkownik)

On April 27th 2016, Carlos Gonzalez Juste (2nd year post-grad intern), Mary Kempski (supervisor and senior conservator) and myself travelled to Deene Park, between Corby and Stamford (Northamptonshire), to take care of 12 paintings that have suffered from mould and record their profiles in order to monitor changes to their panel support curvatures.

Deene House is a sixteenth century property incorporating a medieval manor and has been occupied by the Brudenell family since 1514 up until this day. The house has a grand style, with many paintings of ancestors as well as family heirlooms. As this house is lived in and not a museum, no photos of its interior will be published, only details of the paintings and the work done on them.

The twelve paintings are family portraits dating back from the seventeenth century. They are painted on oak panels by a British artist/studio and represent children and women at various ages. It is not known who they are but it seems likely they were members of the Brudenell family.

Detail of one of the family portraits. (© Polkownik)

The paintings had suffered from humidity and had developed mould on the reverse of the panels. Not all panels were affected: some of them had been restored in 1966, and the reverse had been impregnated with a mixture of wax and resin, which acted as a barrier. The restored panels were thus protected from mould. However, this wax mixture also acted as moisture barrier, and these panels were less affected by the recent lowering of relative humidity in the house, which caused the more sensitive panels to warp and adopt a more pronounced curvature.

The paintings with whitish reverse are coated with wax. (© Polkownik)

This in-situ had three objectives: remove the mould, take the curvature of the panels for monitoring and future comparison, and reframe the paintings to a conservation standard.

The paintings were first taken off the walls. All 12 could not be taken off at once since the space was restricted, which meant we could only work on 4 to 5 paintings at the same. As soon as one was done, it was put back on the wall and another one was brought in.

The mould was first removed using swabs and alcohol (click on photos to enlarge).

This enabled us to then unframe the paintings. A few of them had been restored by the Hamilton Kerr Institute several years before and already had proper framing. The rest were improperly framed, with nails holding the panels in their frames which were restricting their movements and could cause internal stresses. Luckily, no splits had developed or joints opened.

Once the paintings were out of their frames, the curvature profiles were taken on a piece of cardboard, and the current relative humidity and temperature of the room were written down. This will allow us to compare the curvatures at our next visit and understand the sensitivity of the wood to environmental conditions. Charlotte Brudenell (wife of the present owner of Deene Park)  is very committed to giving the paintings the best possible conditions in their setting and is hoping to improve the climate control for the panels and all the paintings in the house.

The frames that had not been recently restored had their rebates lined with acid-free paper and cork spacers to accommodate the panels. Once the paintings were laid down in their frames, they were kept in place with brass strips at the middle of the top and bottom edges, so as to enable the panels to still move across the grain according to the relative humidity fluctuations.  The paintings were then hung back on the wall.

This in-situ was a very good learning experience, as treating 12 paintings in a day was a great challenge, even with three people. It is interesting to see how one improves as the day wears on and how organisation evolves in order to be as economical as possible. Doing repetitive tasks, such as lining rebates and framing, greatly improves one’s skills and efficiency. The size of the artworks, as well as their location in the rooms and proximity to furniture, also required constant teamwork in order to move and re-hang them safely. The Hamilton Kerr Institute will soon return to Deene Park to continue the monitoring and preventive conservation of its artefacts.

Camille Polkownik – 1st year Post-Graduate Intern at the Hamilton Kerr Institute (2015-2017)

About the Author

Ms Camille Polkownik graduated with a Master Degree in the Conservation and Restoration of Paintings in 2014, from the École nationale supérieure des arts visuels de La Cambre in Brussels . She also has a Bachelor degree in the Conservation and Restoration of Painted Works (2011) from the Superior School of Fine Arts, in Avignon, France. She has interned in the Royal Institute for Culture Heritage (KIK-IRPA, Belgium), the Museum of Fine Arts in Nice (France), in private studios and at the Art Gallery of New South Wales (Sydney, Australia).

To contact Camille Polkownik:


In-situ in Southern England

From the 6th to the 8th of April 2016, Senior Painting Conservator Christine Slottved Kimbriel and I (Carlos González Juste, 2nd year postgraduate Intern) worked in-situ treating an altarpiece in a parish church in the south of England. The altarpiece is an Italian tryptich dated to the second half of the 14th century, and currently attributed to Pietro Nelli, a Sienese artist working in the tradition of Giotto.

Details showing the egg tempera technique and the scoring and punching embellishing the gilt halo and the crozier. (© González Juste)

Like with many art objects not kept in a museum environment, this altarpiece has to face typical church conditions, including changes in temperature and relative humidity, the occasional birds droppings, and also the effects of the presence of bats which frequent the building.

Frequent and uncontrolled changes in relative humidity have an adverse effect on panel paintings, as wooden supports tends to respond with expansion and contraction. These movements affect not only the panel (- which may split if it does not have space to move in the frame) but also the paint layers and gilding, producing cracks, flaking and subsequently paint loss.

Bats are common in churches and their roots are protected by legislation. The damage produced by the corrosion of their urine and guano can be considerable, especially on the painted surface where it damages both the varnish and the paint.

The in-situ work on the altarpiece started with a full visual examination of the three panels, their structure and frame. In spite of its overall sound state of preservation, the altarpiece required consolidation of loose and vulnerable areas of paint and gilding, both on the panels and on the 19th century gilt frame. After consolidation with Lascaux© Medium for Consolidation, surface dirt and several bird droppings were removed, some areas of deteriorated varnish saturated with new varnish application and losses filled and toned. The project required us to work from a scaffolding in order to reach all areas of the panels. The surface cleaning removed a considerable build-up of surface dirt and produced a significant improvement to the general appearance of the painting, allowing the astonishingly well-preserved bright colours of the robes and the delicate flesh tones of the faces to come across once again.

Some minor technical investigation was undertaken, and in spite of the challenging conditions of working in-situ and under a time constraint, close optical examination and local infrared photography was accomplished, providing some interesting results.

White garment of St Julian during surface cleaning. (© González Juste)

It is quite common that members of the Institute have to travel to work in-situ in churches, country houses or local museums. The reasons for choosing to work on site, rather than bringing the work to the studio, vary. It may be the right option when the painting is particularly heavy or large, or when its absence is considered unacceptable, as may be the case for an altarpiece that plays a vital part in daily worship. A painting can also be in a particularly delicate state of preservation that necessitates work being undertaken prior to moving the object, or conversely, one or more paintings are in need of only minor, preventive or aesthetic intervention that can be done more cost-effectively on site.

González Juste undertaking surface cleaning. (© Kimbriel)

In-situ jobs are always very interesting and useful opportunities for interns, as they give us the opportunity to visit and discover different parts of the country, and especially their works of art. It also helps interns to develop their abilities when they have to face treatments in challenging circumstances and under time pressure, far away from the well-equipped studio. In-situ jobs not only provide the gratification of a job well done, but it also sometimes includes the privilege of seeing how conservation work can have positive repercussions on the daily life of the surrounding community, as was the case here. Having the opportunity to work on a magnificent altarpiece in a beautiful location was truly a pleasure, not least thanks to the helpfulness and interest of the church community, who were eager to see this beautiful work of art to which they feel attached preserved and safe for the foreseeable future.

Carlos González Juste – 2nd year Post Graduate Intern at the Hamilton Kerr Institute.

Senior Painting Conservator Christine Slottved Kimbriel explaining the treatment and characteristics of the altarpiece to members of the community. (© González Juste)

About the author

Carlos González Juste has a B.A. in History from the Complutense University in Madrid and a Degree in Conservation and Restoration of Cultural Heritage from the Escuela Superior de Conservación y Restauración de Bienes Culturales in Madrid.  He has interned in the Museo Nacional del Prado (Madrid) and other Spanish institutions. He is currently completing his second year as a postgraduate Intern at the Hamilton Kerr Institute, University of Cambridge, where he has been working on a wide range of projects, from early Italian paintings, such as the Master of the Castello Nativity, to early C20th Russian artist A. Harlamoff, besides paintings by J. Reynolds, W. van Mieris and the C17th English painter R. Buckett.

To contact Carlos González Juste:

In-Situ at Weston Park, Staffordshire

weston park view reduced
Front view of Weston Park. (© 2016 Kari Rayner)

Weston Park is a 17th century manor house owned by the Weston Park Foundation. It has been the seat of the Earls of Bradford since the 17th Century. The house is now open to the public for visits and guided tours in addition to offering venue for conferences, weddings and other events. The collection at Weston Park includes beautiful pieces of furniture, ceramics, tapestries and an impressive collection of paintings that hang in every room, including works by Van Dyck, Holbein the Younger, Thomas Gainsborough, Sir Joshua Reynolds and George Stubbs. For 20 years, these paintings have been the subject of annual in-situ visits by the Hamilton Kerr Institute, which has mainly focused on remedial, preventive and simple aesthetic treatments. This week usually takes place during the Manor’s off-peak season, allowing the conservators, including students and interns, to stay on site during this time in the highest of style!

In February 2016, senior conservator Mary Kempski headed up a team of four interns, Kari Rayner, Sarah Bayliss, Carlos Gonzalez Juste and Sven van Dorst, for the Weston Park in-situ. The work was carried out in the Music Room, a long, spacious room decorated mainly with paintings of the family’s champion horses. Over the week, we treated 16 paintings and their frames performing such tasks as surface cleaning, consolidation, revarnishing and conservation framing.

Setting up in the Music Room. (© 2016 Sarah Bayliss)

As with most in-situ projects, some of the paintings worked on would have benefitted from more interventive treatments, such as varnish and overpaint removal. However, as time, space and resources are limiting factors with regard to in-situ work, stabilising the paintings and improving their framing was of primary importance. However, there are several ways to improve a painting’s aesthetic in close confines; surface cleaning drastically improved the visibility in a number of paintings, and as varnishes often become less saturating over time, revarnishing as needed with a stable synthetic varnish such as RegalrezTM was an excellent way of restoring some of the saturation and depth to paintings. This can also help with evening the overall gloss, particularly when previous restorations have aged and become matter over time.

Another important part of the work as part of this in-situ project was to improve the framing of paintings. In the past many paintings were held in the frame by nails, which often damages the stretcher and tacking margins and make the painting difficult to safely remove. Framing can be improved by lining the frame with paper tape and felt, so that the paint surface has a cushion to rest against rather than wood of the frame. Fixings are replaced by brass plates that are screwed in, allowing paintings to be easily removed from the frame in the future. Stretcher keys can sometimes become loose and fall down in between the canvas and stretcher, resulting in damages to the canvas and paint layers: this can be prevented by tying the keys to the stretcher. A Tyvek® backing was added to the reverse of all of the frames to cover the backs of the paintings. This acts as a barrier, protecting the back of the painting from knocks, water damage and the ingress of dirt.

Documentation is also important part of an in-situ visit, as unframing paintings allows them to be properly evaluated for condition and potential issues that might cause problems in the future. Flaking paint and the weakening of the painting’s structural support (for example, the tearing of canvases or splits in wooden panels) are issues which can often be addressed in-situ, but may require further or more elaborate treatment in the studio. This condition checking of paintings is an important part of collection care, and can nip problems in the bud and prevent greater damage to the paintings from neglect.


During our in-situ at Weston Park, there were several opportunities for us to interact with the public and spread the word of conservation! This primarily took the form of ‘conservation in action’ tours, in which people were bought in to see what we were up to. This allowed individuals to directly ask us questions about the treatments of the painting, and also more generally about what we do as conservators. In addition to these tours, we were hounded by the Shropshire press. Mary Kempski and Sarah Bayliss appeared on the local radio talking about painting conservation, the Hamilton Kerr Institute and the in-situ project at Weston Park. The following day, reporters from the Shropshire Star interviewed Mary and took photographs of us in action.

It was refreshing for us to see the staff at Weston Park taking an interest in our work and to have facilitated our engagement with the local community, and we hope by sharing our experiences through this forum to equally engage a wider audience with our profession.

Sarah Bayliss – 1st year Post Graduate Intern at the Hamilton Kerr Institute

About the author

Ms Sarah Bayliss is a graduate of the Post-graduate Diploma in the Conservation of Easel Paintings at The Courtauld Institute in London. She also has a Master of Chemistry from the University of East Anglia in Norwich, UK.

To contact Sarah Bayliss:

In Situ at Middle Temple, London

Summary of our in situ at Middle Temple, London, 26-30/10/2015


Panorama of Middle Temple (© Middle Temple)





From the 26th to the 30th of October 2015, Amiel Clarke (2nd year student), Kari Rayner (1st year Post Graduate Intern), Sarah Bayliss (1st year Post Graduate Intern) and myself (1st year Post Graduate Intern) accompanied Senior Painting Conservator Mary Kempski to Middle Temple in London (

Middle Temple is one of the four Inns of Court which have the exclusive right to call students to the Bar. One of Middle Temple’s main functions now is to provide education and support for new members to the profession. It is also a professional society with international members. Middle Temple is located in the wider Temple area of London, near the Royal Courts of Justice. One of their core purposes is the maintenance of the Inn’s estate and its historic heritage: this is where we painting conservators come in.

We were called to treat paintings with various damages, such as small tears, scratches in the varnish or matt spots, and the accumulation of heavy grime. The specific setting at Middle Temple presented additional complications and required problem solving as a team.

The work was done on site, as the paintings needed minor treatments. The challenge was twofold: conserving 7 paintings, mostly portraits, in four days and doing so in a restricted space. This meant collaborating with each other at all times, as some of the paintings were large and could not be moved single-handedly. The configuration of the room also had to be modified numerous times in order to swap the artworks around and allow framing on the tables.

This on-site job was beneficial for both student and interns, as it taught us to work closely with each other.  Repeating the treatments on the frames helped us get better and faster at framing: lining the rebate with both brown paper and felt, measuring and cutting balsa spacers to prevent the painting from slipping in the frame, applying soft backboards made out of Tyvek…Having the chance to work in such a secret and beautiful environment is always a benefit, especially when areas are not open to the public and we would not have had the occasion to visit Middle Temple otherwise. We would like to thank Lesley Whitelaw, Senior Archivist at Middle Temple, for making our stay so enjoyable, and will now let the photos speak for themselves.

Camille Polkownik – 1st year Post Graduate Intern at the Hamilton Kerr Institute

Ms Camille Polkownik graduated with a Master Degree in the Conservation and Restoration of Paintings in 2014, from the École nationale supérieure des arts visuels de La Cambre in Brussels . She also has a Bachelor degree in the Conservation and Restoration of Painted Works (2011) from the Superior School of Fine Arts, in Avignon, France. She has interned in the Royal Institute for Culture Heritage (KIK-IRPA, Belgium), the Museum of Fine Arts in Nice (France), in private studios and at the Art Gallery of New South Wales (Sydney, Australia).

 To contact Camille Polkownik :