Paint… and butterflies? Conserving and researching a painting by Otto Marseus van Schrieck

Sophie Lamb, postgraduate intern

Flowers, Insects and Reptiles by Otto Marseus van Schrieck is an oil painting on canvas, dated 1673. This work was brought to the Hamilton Kerr Institute for treatment and investigation, after receiving generous support from the Woodmansterne Art Conservation Awards in 2019. The painting belongs in the Fitzwilliam Museum collection. It was bequeathed in 1834 by Daniel Mesman and is one of three paintings by this artist in the Museum. Only two other paintings by van Schrieck are held in public collections in the UK.

Otto Marseus Van Schrieck, 1673. ‘Flowers, Insects and Reptiles’: before treatment. Photograph © Chris Titmus, Hamilton Kerr Institute.

Flowers, Insects and Reptiles depicts a nocturnal gathering of creatures by the edge of a pool of water. The grouping is lit by pale light coming from the left-side of the composition. From a mossy patch of earth in the foreground springs a cluster of thistles, weeds, carnations and a rose, and around this composition are numerous butterflies and moths, dragonfly, lizard and a snake, which snaps out from behind a leaf at a passing butterfly.

Otto Marseus van Schriek was a Dutch-born painter active in the later part of the seventeenth century. He travelled to Rome early in his career and later set up his home and studio in the marshy outskirts of Amsterdam known as “the land of snakes” (Jorink, 2014). He is known for creating a signature genre of painting, the forest floor still-life, which is often termed sottobosco in Italian. This genre developed from conventional floral still-life painting, shifting the floral ensemble out of vases and into the forest, resulting in eye-level portrait of the dark world of the undergrowth and the creeping fauna that inhabited it. His works teem with reptiles and amphibians, toads and snakes, and, hovering above, butterflies and moths.

Otto Marseus Van Schrieck was fascinated by animals and was especially intrigued by the small reptiles and amphibians that could be found around the ponds and wetlands near his home, just outside Amsterdam. Collectors and dealers visiting his studio would be shown the menagerie of snakes and creatures he bred and kept as models for his paintings. He spent so much time hunting around the damp woodland and undergrowth that he earnt the nickname ‘Snuffler’ amongst the circle of painters he socialised with (ibid.). Van Schrieck worked on the borders of art and science (Seelig, 2018); he was interested in Natural History and especially in the discussions around spontaneous generation, which is reflected in the accuracy of the animals depicted in his works, although set in fanciful imaginative situations.1

A close-up detail of the snake and butterfly. Photograph © Hamilton Kerr Institute.

Van Schrieck’s technique and use of butterflies

Van Schrieck was commercially successful in his lifetime, and so would have developed a methodical approach to painting, since it would be economically effective to do so (Madeleine, n.d.). In terms of the materials he used, it is likely that he did not prepare his own canvases, since readily prepared canvases were available to buy in the Netherlands at the time (Wallert, 1999). A canvas maker would typically size the linen canvas with an animal glue such as rabbit skin, in order to protect the fabric from the potentially damaging effects of oil paint. Following this a ground layer would have been applied to provide a suitable surface on which to paint. This painting has a reasonably thick application of a white ground, which may be either lead or chalk based. It was often the case that an artist would apply a second layer of priming in a preferred colour to work on; however, it is not clear whether van Schrieck applied this second priming before painting (Howard, n.d). He would then start by making a detailed drawing on the priming; artists contemporary to van Schrieck were known to make the underdrawing in silverpoint, black chalk, or ink. The painting would then be built up in layers, consisting of an imprimatura (a first wash of a single colour), then the dead-colour (a flat wash of colour for each form depicted), followed by successive layers of glazes to model shadow and form, and finally fine details such as patterns and highlights (ibid.).

Van Schrieck carefully arranged the composition of the intertwining thistle, flowers and reptiles to give an illusion of movement and depth. For example, the thistle shown in the left of the foreground is depicted convincingly in a three-dimensional space; pale light reflects off its prickly edges. The lighting of the scene is complex with emphasised contrasts of light and dark, and this gives it a sense of tension and movement. One feature stands out arousing curiosity: the butterflies. These have a stiff and static appearance, which contrasts with the naturalistic depiction of the foliage and reptiles around them. The butterflies appear noticeably pale and yellow against the dark background, as if they exist in a plane superimposed onto the rest of the composition.

On inspection under a microscope, a regular pattern of minute scales can be discerned on the butterflies’ painted wings (Webexhibits, n.d.). Van Schrieck practised the unusual technique of pressing butterfly wings into wet paint so that the tiny scales remained caught in it, and the butterfly’s natural colours became a part of the painting. Using a brush he would then paint in the body and make small corrections. In order for the wings not to disappear against the dark background paint, a butterfly-shaped reserve would have been created in white prior to their application, to allow reflected light to shine through their colours (Steensma, 1999). This technique, which has been identified in other works by van Schrieck, is also evident on this painting (Ibid; Beier, 1987).

Opinions differ about precisely how the scale transfer technique was carried out; one theory is that van Schrieck pressed the wings directly onto a prepared patch of paint in the shape of the butterfly (Steensma, 1999). Another idea cites a set of instructions for a ‘double-pass’ technique whereby the wings would be first pressed to dry between sheets of paper coated with gum arabic. On peeling the wing membrane away, the scales would remain adhered to the gum arabic. The paper sheet would then be cut to the outline of the wing, and this would be placed face down onto freshly varnished paint. This would then be left to dry. Since varnish is hydrophobic, the scales could be released from the paper using water, leaving them embedded in the varnish the correct way up (Berthier et al, 2008).

The butterflies have greatly changed in appearance since they were applied fresh. Most of the scales have faded due to exposure to light – the effects of even small doses of UV light exposure will accumulate over time – and have now become colourless. Their yellow appearance is due to the presence of an overlying discoloured varnish. Some reddish scales have not faded, and enough remains to help with the identification of the corresponding species (with thanks to Russell Stebbings of the department of Zoology, University of Cambridge, for his help). The butterflies in this painting were identified as being native to the Netherlands and would have been also native to Cambridge, although the Large Tortiseshell is now considered extinct in the UK and the Garden Tiger Moth is declining in numbers.

Condition of the painting

Although the painting was in a stable condition when it arrived, its image was partially obscured by multiple layers of very old, non-original natural resin varnish that had degraded. This substantial varnish layer had become hazy, extremely yellowed and rather opaque, making it appear as if one were peering at the scene through thick fog. The dulled original colours and their reduced tonal range resulted in the loss of the sense of depth and many details of the artist’s intended composition were obscured, including the skyline and the intricate detail of the foliage. It was decided that removing the discoloured varnish would greatly improve the appearance of the painting and restore these aspects that are so central to van Schrieck’s oeuvre and philosophy. The application of a new varnish would then re-saturate the colours and provide renewed protection to the paint surface.

Conservation treatment

Minute paint samples were taken from two locations (one from the background and one from a butterfly wing) in order to ascertain whether it would be possible to safely clean the varnish without affecting the delicate paint layers. Examination of the samples in cross-section indicated that there were at least four layers of varnish present. These samples further showed that the scales were placed onto the painting and then varnished. The scales appear to be embedded in a varnish layer, possibly the varnish used during the double transfer method. This is, however, distinct from the main upper varnish. It was decided, following a series of testing and further observations, that cleaning this later coating gradually whilst leaving the imbedded scales intact would be possible.

Cleaning of the painting is currently underway. The painting also presented a layer of modern synthetic varnish, which was applied when the painting last visited the Hamilton Kerr Institute in the mid-1990s in preparation for an exhibition. This topmost varnish was removed first before the older discoloured natural resin varnishes were tackled. A water-based method of cleaning was developed to safely remove these layers gradually, avoiding the excessive use of organic solvents and swab action which could potentially disturb sensitive layers such as oil glazes or the varnish containing the embedded scales.

The treatment is ongoing at the time of writing this blog. Once the varnish has been cleaned from the paint layers, I aim to carry out further technical examination to gain more understanding of the pigments, binders and the technique used, in particular the butterfly scales application. I will then fill and retouch any losses to the paint layer whilst leaving the butterflies untouched. Afterwards a final varnish will be applied. I am also working on reconstructing the technique so that I can learn how it might have been used, but also to gain a glimpse of how the painting may have appeared originally. We know that the butterflies and moths have drastically changed over many years and it is not possible to restore their original appearance on the painting, but it might at least be possible to see the original intention on a reconstruction.

Conserving this painting is an interesting challenge in terms of trying to find a safe way to clean the painting whilst preserving the very fragile remains of the butterfly wings, especially since the artist’s precise method for transferring the scales is not yet fully understood. It is hoped that this project will bring new insight into the study of van Schrieck’s painting methods, and perhaps open further research into experiments with embedding organic material in paintings and methods for treating them. Flowers, Insects and Reptiles is proof of van Schrieck’s inventiveness and skill as an artist and of  his parallel interest in the natural world.

Many thanks to Alice Tavares da Silva, Henrietta Ward and Russell Stebbings for their guidance and support.

With thanks to the Woodmansterne Art Conservation Awards for their generous support in funding this project.


Beier, B., 1987. >>Contre-Epreuves<< in der barocken Stillebenmaleri. Maltechnik 1. Restauro. pp. 35-39.

Berthier, S. ; Boulenguez, J. ; Menu, M. ; Mottin, B. 2008. ‘Butterfly inclusions in van Schrieck masterpieces’. Techniques and optical properties. Applied Physics A, 2008. 92(1). pp.51-57.

Howard, H. N.D. Support and Ground. The National Gallery. [online] Available at: Accessed 9th March 2020.

Jorink, E. 2014. Snakes, Fungi and Insects. Otto Marseus van Schrieck, Johannes Swammerdam and the Theory of Spontaneous Generation, in: K.A.E. Enenkel, P.J. Smith. eds., Zoology in Early Modern Culture. Intersections of Science, Theology, Philology, and Political and Religious Education. 32(2014). pp. 197-234.

Levine, R. and Evers, C. 1999. The Slow Death of Spontaneous Generation (1668-1859). [online] Access Health @ the National Health Museum. Available at: Accessed 12 March 2020.

Steensma, S. 1999. Otto Marseus van Schrieck: Leben und Werk. Hildesheim; Zurich; New York: Georg Olms Verlag.

White, M. N.D. The Highly Systematic Methodology of Dutch 17th-century Painting Techniques. [online] Available at: Accessed 27 March 2020.

Wallert, A. 1999. Methods and materials of still-life painting in the seventeenth century. In: A. Wallert, ed. 1999. Still Lifes: Techniques and Style: An Examination of Paintings from the Rijksmuseum. Zwolle: Waanders Publishers. Webexhibits. N.D. Causes of Color: Butterflies. [online] Available at: Accessed 27 March 2020.

About the author:

Sophie Lamb graduated in 2018 with an MA in the Conservation of Fine Art (Easel Paintings) from Northumbria University. Prior to this she completed her BA (Hons) in Fine Art from Oxford Brookes University. While there she won an Erasmus scholarship to study oil painting and drawing at the Vilnius Academy of Art. Additionally, she studied on the foundation year in Engineering and Physical Sciences at the University of Manchester. Her projects at Northumbria included treating a 19th century painting on millboard, which led on to an extended research project investigating unusual materials for painting supports and investigating an 18th century painting on papier-mâché board. During her training she undertook conservation internships with the V&A museum and with various private conservation studios around London and East Anglia. 

To contact Sophie:

Restoring a Landscape with Figures

Many of the paintings that come through our studio have had a long and eventful history. One such painting, Landscape with Figures attributed to the School of Teniers (Fig. 1) falls into this category. This blog describes the plucky painting’s road to recovery, and shows how paintings can be transformed with some TLC.

When brought to the Institute, the painting was in poor condition and in need of structural and aesthetic treatment. The original canvas was beginning to peel away from its old glue-paste lining and damage and wear to the paint layers, caused from harsh cleaning by previous restorers, was also evident and needed addressing. The raking light photo of the painting before treatment (Fig. 2) shows that the painting had severe undulations that related to the condition of its canvas support.  The tacking margins were so degraded that in many places the canvas was no longer attached to the stretcher.

Figure 1: Landscape with Figures, whole front, before treatment (©Titmus)
Figure 1: Landscape with Figures, whole front, before treatment (©Titmus)

Figure 2: Landscape with Figures, whole front raking light from the bottom, before treatment (©Bayliss)
Figure 2: Whole front raking light from the bottom, before treatment (©Bayliss)


Before the structural work began, the painting was cleaned. The varnish present on the painting was blanched and the painting appeared unsaturated as a result (Figs. 3 & 6 ). Both the varnish and overpaint were removed with solvents (Figs. 4 & 7). Brown overpaint had probably been applied to mask the severely abraded paint layers and the removal of this overpaint allowed us to appreciate certain details of the painting that were previously hidden. A horse and rider were discovered in the bottom right hand corner (Figs. 6 & 7 & 8), and the hawk (Figs. 3 & 4 & 5), which had been visible but completely swamped by the surrounding overpaint, was suddenly part of the narrative again.


Structural treatment

The painting has a large tear in the top left hand section that had gone through both original and lining canvases. A wax patch had been adhered over the tear on the reverse before the tear was filled and retouched from the front (Fig. 9). It was decided that the painting required re-lining, as the original canvas no longer had the capacity to support the paint layers. Lining is an interventive technique that in the past was often carried out on paintings as a preventive measure. Thoughts and fashions change though, and lining is really only considered now as a last resort when structurally treating a painting. However, it was certainly necessary in this case, considering the poor condition of the painting.

The painting had been glue-paste lined in the past, and we decided to re-line the painting using the same method. Glue-paste lining has been the traditional method in Britain and while it is less commonly used these days, it is sometimes used for paintings that have tears that need supporting (as in this case), or badly cupping or flaking paint.

Firstly, the painting needed to be de-lined – the old lining canvas and lining adhesive removed. The painting was faced (a process where tissue paper is glued onto the front of the painting in order to protect it) and then placed face down on a covered board. The tacking margins were so degraded that they could be gently pulled away from the stretcher.


Before de-lining, the wax patch was peeled away from the lining canvas using white spirit to soften the wax (Fig. 9). The painting was de-lined carefully, leaving the original canvas with much of the lining glue-paste present on the back of the painting (Fig. 10). This glue was mostly brittle enough to be scraped away with a blunt knife (Fig. 11 & 12). However, some of the glue could not be removed in this fashion. Laponite (a synthetic clay) was applied which swelled the glue-paste allowing the glue to be scraped off. De-lining, revealed a small gap between the sides of the canvas along part of the tear. This was filled by the addition of a canvas insert of sized linen.

A new, linen lining canvas was prepared. For the lining, a layer of warmed lining adhesive was applied to the lining canvas. The painting was laid on top of the glue and gently padded down to smooth it down and make sure there weren’t any trapped air bubbles between the canvases. The painting was ironed through four layers of canvas, and the temperature of the paint was constantly checked by hand (Fig. 13). Although the iron used in this process looks ridiculously large and heavy, as its weight is spread out over a large area it does not exert too large a pressure on the paint. Raking light was used to check the texture of the surface and a cold iron was used in some areas to chill and set the paint to the work out any distortions. After this first ironing, the facing was changed and the painting ironed again in a similar fashion.

The painting was left to dry for several days before the facing was removed. Since the result of the lining was satisfactory, a coat of BEVA was applied onto the reverse of the lining canvas to act as a moisture barrier before the painting was re-stretched.

Filling, varnishing and retouching

The painting was varnished and retouched using Gamblin© Conservation Colours. The wear and losses in the paint layers were retouched imitatively to a standard thought appropriate for the condition of the painting. Touching out the wear in the foreground helped to solidify the landscape and reintroduced a recession into the distance.

Figure 17
Figure 17: Landscape with Figures, whole front, after treatment (©Titmus)

Figure 18
Figure 18: Landscape with Figures, whole front raking light from bottom, after treatment (©Bayliss)

This was a wonderful project, allowing me to gain experience in lining and treading that fine line of re-intergrating a badly damaged image. There is obviously a narrative going on between these figures and the idyllic landscape now brought back to life, although we still don’t know exactly what’s happening in this painting. But this is certainly part of its charm and no doubt it will continue provoking the question, “what is going on?!” for many years to come.

Figure 19
Figure 19: Detail of startled man (©Bayliss)

The grass is always greener on the other side: conservation of the Portrait of Elisabeth de Valois

This oil painting on oak panel representing Elisabeth de Valois is a copy of the famous portrait originally painted by Anthonis Mor (c. 1517-1577), a Netherlandish portrait painter active mid-16th century (Fig. 1). The painting belongs to the Fitzwilliam Museum, and came to the Institute for assessment before the exhibition: Degas: A Passion for Perfection (3 October 2017 – 14 January 2018).

Fig. 1. Portrait of Elisabeth de Valois, copy after Anthonis Mor by unknown artist, late 16th century, Fitzwilliam Museum. (© Titmus)
Fig. 1. Portrait of Elisabeth de Valois, copy after Anthonis Mor by unknown artist, late 16th century, Fitzwilliam Museum. (© Titmus)

Elisabeth de Valois (1545-1568) was the eldest daughter of Henry II of France and Catherine de Medici and married Philip II of Spain as his third wife when she turned 14. The original portrait was painted by Mor in 1565, when she was 20. Elisabeth died at 23, after miscarrying for the second time in 1568.

The Fitzwilliam portrait, although not by Anthonis Mor, is a faithful copy in a style extremely close to that of Mor. The original portrait has been copied many times by different artists with varying degrees of accuracy. The copies highlight her importance and maybe her popularity, and were likely made to be sent around Europe to the various Royal Courts. The copies of the original portrait (Fig. 2) show her in this exact costume, but the formats vary: portraits only, full length, half length… you name it! The Fitzwilliam version was acquired in 1909, along with a full length portrait of her husband on canvas.

Fig. 2. Collage of all the portraits 
Fig. 2. Collage of all the portraits of Elisabeth de Valois


Dendrochronology analysis was done to find out an approximate date of usage for the panel. Dendrochronology (or tree-ring dating) is the dating technique that utilises the pattern of rings widths within a timber to determine the calendar period during which the tree grew. This is then matched to an existing database. The date of a tree-ring sequence must not be confused with the date of usage of a tree, as sapwood (which has the latest growth rings) is usually removed by panel markers. The analysis provides either a felling date range (when sapwood is present) or a terminus post-quem (when the sapwood is not present).  Between the felling of the tree and the start of a painting, a fair amount of time can go by, as the wood travels and is often seasoned. The results of the analysis indicates a usage date for the wood after 1552 [1].

Condition of the painting

Although the portrait had a number of areas where the paint was flaking and vulnerable (Fig. 3), which were consolidated with sturgeon’s glue, it was in good overall condition.

Fig. 3. Detail of lifting and flaking of the paint layer in raking light. (© Polkownik)

The varnish that covered the surface had slightly yellowed, dulling the colours and flattening the fabulous dress full of jewellery worn by the sitter (Fig. 4).

Fig. 4. Detail of the yellow varnish on the jewels (© Polkownik)
Fig. 4. Detail of the jewelled costume covered by yellowed varnish (© Polkownik)

However, one thing really drew the eye: the lime green background . One could see the background looked dubious and was likely to have been overpainted (Fig. 5). Some fake cracks had also been painted in the background around the face, to try and integrate the area better, and the overall surface was cracked, reminding crocodile skin. It was decided with the curators to do some testing and find out if it was possible to remove the overpaint, what was underneath and what condition it was in. 

Fig. 6. Detail of the background (© Polkownik)

After close observation under the microscope, we came to the conclusion that most of the surface was covered by overpaint (Fig. 6).

Fig. 5. Diagram showing the overpaint (in red). (© Polkownik)
Fig. 6. Diagram showing the overpaint (in red). (© Polkownik)


A paint sample was taken and set in resin (cross-section). The sample showed the original paint layer (2-3) was covered with two thick layers of overpaint (4-5) and non-original varnishes, tinted (6-7) and untinted (8-9) (Fig. 7).

Fig. 7. Paint sample set in resin (cross section) (© Polkownik)
Fig. 7. Paint sample set in resin (cross section) (© Polkownik)

Conservation Treatment

During testing, it was revealed that the overpaint could easily be removed. Three areas were tested; two showed an original paint layer underneath that appeared in good condition, and one test showed an abraded area. It is a difficult decision to remove such a large area of overpaint based on the three small test patches. But as the cleaning progressed (Fig. 8), it became clear that we were right to do this: the background was in good condition, apart from a small abraded area in the background close to the back of the head of the sitter. It seems astonishing that such a small damage warranted the overpainting of the whole background.

Fig. 8. During cleaning (© Polkownik)

The original background is a dark green/brown, showing variations in opacity and in brush handling. It looks vibrant and lively, and complements the sitter’s red dress and pale rosy carnation.

Fig. 8. After cleaning (© Polkownik)
Fig. 9. After cleaning (© Polkownik)

After the removal, the painting was varnished (Fig. 9), the losses filled (Fig. 10) and retouched (Fig. 11) with reversible materials, and the abraded areas in the background were lightly dotted in. Treating this painting stabilised the materials (through the consolidation of flaking paint)  and brought it a step closer to its original 16th-century style.

Fig. 10. After filling (© Polkownik)

Fig. 10. After retouching (© Titmus)
Fig. 11. After retouching (© Titmus)

Camille Polkownik, 2nd year Post-Graduate Intern (2015-2017)

About the Author:

Ms Camille Polkownik graduated with a Master’s Degree in the Conservation and Restoration of Paintings in 2014, from the École nationale supérieure des arts visuels de La Cambre in Brussels (Belgium). 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 at the Royal Institute for Cultural Heritage (KIK-IRPA, Belgium), the Royal Museums of Fine Art of Brussels (Belgium), the Museum of Fine Arts in Nice (France), the Art Gallery of New South Wales (Sydney, Australia) and in private studios.

Her current research projects include the study of extenders added to Prussian Blue; the quality variations in lead white and how they affect paint properties; and the characterisation of Prismatic Lead White, an unusual form of lead white, through X-ray Diffraction analysis and Polarised Light Microscopy.

To contact Camille:

[1] Tyers, Ian, Dendrochronological Consultancy Report 907, pp. 1-4.

Tickled Pink: Unexpected Discoveries in the Painting Technique and Treatment History of Pinturicchio’s Virgin and Child

Virgin and Child with Saint John the Baptist (Fig. 1a-1b) was brought to the Hamilton Kerr Institute for treatment in the spring of 2016 prior to the painting’s display in the Madonnas and Miracles exhibition. While the painting’s condition was stable when it arrived, the varnish was dull and slightly greyish, and it was decided that varnish removal would provide an aesthetic improvement. Although the treatment was not particularly complex, I found studying the materials and techniques Pinturicchio used in this work and researching the painting’s treatment history to be a rewarding and edifying experience.

Virgin and Child dates to 1490-1495 and was acquired by the Fitzwilliam Museum in 1880. This work is only one of numerous paintings by Pinturicchio of this subject, with two of the most closely related versions in the Ashmolean Museum of Art and Archaeology and the Philadelphia Museum of Art. Variations in the paint handling and quality of these works may be attributed to the involvement of workshop assistants.

Materials and Technique

Pinturicchio painted the Fitzwilliam’s Virgin and Child primarily in egg tempera, enriched with oil glazes and gilding. As was traditional in Italian paintings of this period, the flesh tones are underpainted with a greenish layer termed verdaccio. Additionally, dispersed pigment samples were taken from the Virgin’s robe, and the pigment was identified as high quality coarse azurite using polarized light microscopy. Unfortunately, the robe appears much darker and less three-dimensional than it would have been when first painted. As often occurs with azurite, the paint has discoulored from aged medium and varnish, and the paint layer has suffered abrasion from past restoration treatments. When initially painted, the robe would have been a bright blue and would have appeared to drape more realistically: examination of the painting using infrared reflectography (Fig. 2) revealed extensive underdrawing in a liquid medium, and folds in the robe were both underdrawn and possibly outlined with carbon-containing black paint.

Fig. 2 Infrared reflectogram of Virgin and Child (©Titmus)
Fig. 2 Infrared reflectogram of Virgin and Child (©Titmus)

Perhaps the aspect of Pinturicchio’s technique I found most intriguing, however, was his method of underpainting. Microscopic (Fig. 3) and cross-sectional analysis of the paint layers in the Virgin’s robe revealed a locally-applied pink underlayer. John Brealey, the paintings conservator who treated the painting previously, estimated this layer to contain madder – a red lake – although analysis was not undertaken to confirm this identification. This underlayer does not seem to have been modelled to any significant extent, since the radio-opacity in the X-radiograph is quite even.

Fig. 3 Microscopic detail of pink paint showing through the abraded azurite of the Virgin’s robe in Virgin and Child (©Rayner)
Fig. 3 Microscopic detail of pink paint showing through the abraded azurite of the Virgin’s robe in Virgin and Child (©Rayner)

The purpose of a pink or red underlayer in the mantle would have been to warm the resulting hue once the blue paint had been applied, as azurite can sometimes appear greenish. As Christine Kimbriel and Youjin Noh explore in “Sebastiano del Piombo’s Adoration of the Shepherds: On the Pursuit of Colouristic Splendour in a ‘Lost’ Painting,” it was not uncommon to find blue over pink or red underlayers in fifteenth-century and early sixteenth-century Venetian painting.1 Kimbriel and Noh cite examples of paintings by Giovanni Bellini, Sebastiano del Piombo, and Giorgione with this type of layering.

In contextualizing Pinturicchio’s use of this type of layering, it became clear that there are extant examples of works containing underpainting of lead white and red lake underneath blue robes or sky from as early as the fourteenth and fifteenth century, including paintings by Giotto.2 Raphael, who came to prominence only a generation after Pinturicchio, is perhaps the best-known example of a central Italian artist using this method.3

Additionally, this type of layering was a common technique in the painting of frescoes. For example, a layer of red ochre underlies azurite pigment in Perugino’s The Circumcision of the Son of Moses in the Sistine Chapel.4

While the presence of this pink layer in Pinturicchio’s Virgin and Child was initially surprising, it became apparent through research that the artist’s technique follows a tradition of employing pink and red underlayers under blue for optical purposes.

Elisabeth Petrina, 1st year student, used the information and reconstructed this painting with historically-accurate materials.

Treatment History

It is not often that documents recording the historic treatment of paintings exist, but when they do, they can afford the opportunity to reflect upon past conservation practices and study how specific restoration materials have aged. This was found to be the case with Virgin and Child, which was previously treated by John Brealey (1925-2002) in 1964. Brealey was a prominent figure in the history of paintings conservation, and his ideas and philosophies have had long-lasting significance for the field. He was a member of the advisory council of the Hamilton Kerr Institute at the time he treated this painting, and he left London in 1975 to become the chairman of paintings conservation at the Metropolitan Museum of Art.

The treatment report and photographs of Virgin and Child indicate that a good deal of previous restoration was removed by Brealey, but some old retouching and gilding was left. In Brealey’s words, “The gold hatching indicating the highlights is bogus, but has been left on because there must have been something similar on originally.” The thinking described in the treatment report is in line with Brealey’s well-known philosophy of selective cleaning. Ultraviolet examination of the painting (Fig. 4) confirmed that retouching from at least two campaigns of restoration were still present: Brealey’s and at least one previous restoration.

Fig. 4 Ultraviolet light photograph of Virgin and Child before treatment showing numerous campaigns of previous restoration (©Rayner)
Fig. 4 Ultraviolet light photograph of Virgin and Child before treatment showing numerous campaigns of previous restoration (©Rayner)

Significantly, the report also specifies that the painting was revarnished with MS2A®, MS2B®, and wax. Both of the MS2® varnishes are ketone resins, with MS2B® having a slightly different solubility and higher viscosity.5 The identification of these coatings accorded with their appearance, since synthetic varnishes can have a tendency to grey and dull rather than yellow like natural resin varnishes (Fig. 5). Knowing the materials used to varnish the painting allowed testing of the theory that the coatings should remain easily reversible over time. While they were certainly still soluble, organic solvents of a surprisingly high polarity were required in order to remove the conservation varnish.

Fig. 5 Virgin and Child during treatment showing varnish removal in progress (©Rayner)
Fig. 5 Virgin and Child during treatment showing varnish removal in progress (©Rayner)


In spite of the unexpected polarity of the synthetic coating, varnish removal was relatively straightforward except for within the Virgin’s blue robe. The coarse azurite in this area was found to be under-bound. This means there was a higher ratio of pigment to oil, not sufficient to fully coat the particles and bind them into the polymerised oil network. Contrary to the rest of the painting, the robe was cleaned using a quickly evaporating solvent on cotton swabs, lightly rolled over the surface, in order to solubilize and reduce the varnish without excess mechanical action.

Significant amounts of overpaint and chalk fill material had been left covering original paint, so treatment also involved reducing these foreign materials under the microscope (Fig. 6). Additionally, discolored brown material within the halo was reduced using aqueous solutions and gels.

Fig. 6 Virgin and Child before retouching (©Titmus)

Unfortunately, I was unable to complete the treatment prior to finishing my post-graduate internship in the summer of 2016. The filling, retouching, and revarnishing were carried out by the Hamilton Kerr Institute’s Director, Rupert Featherstone (Fig. 7).

Fig. 7 Virgin and Child after treatment: Virgin and Child (©Titmus)
Fig. 7 Virgin and Child after treatment (©Titmus)

Although I would like to have seen this treatment from start to finish, I learned a great deal from the opportunity to study this artwork. I hope this text provides some insights into the creation and history of the work, and that you will visit the Fitzwilliam Museum to see Virgin and Child for yourself!

Kari Rayner, 2nd year Post-Graduate Intern (2015-2016)

About the Author:

Ms Kari Rayner holds a Master of Arts in Art History and an Advanced Certificate in Art Conservation from New York University, USA. She also graduated with her 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 completed a year-long post-graduate internship at the Hamilton Kerr Institute from 2015-2016. Kari returned to the NGA in the fall of 2016 as an Andrew W. Mellon Fellow in Paintings Conservation.

To contact Kari:


1 Kimbriel, Christine and Youjin Noh. “Sebastiano del Piombo’s Adoration of the Shepherds: On the Pursuit of Colouristic Splendour in a ‘Lost’ Painting.” In Artists’ Footsteps: The Reconstruction of Pigments and Paintings: Studies in Honour of Renate Woudhuysen-Keller. S.l.: Antique Collectors’ Club, 2013.

2 Sincere thanks to Elizabeth Walmsley of the National Gallery of Art, who shared her expertise in Italian painting and directed me to the following resources on the topic of pink/red underlayers. Borgia, Ilaria, Diego Cauzzi, Bruno Radicati, and Claudio Seccaroni. “Raphael’s Saint Cecelia in Bologna: New Data about its Genesis and Materials.” Raphael’s Painting Technique: Working Practices Before Rome. Proceedings of the Eu-ARTECH workshop. Eds. Ashok Roy and Marika Spring. Page 95

3 Ibid, page 95

4 Santamaria, Ulderico and Fabio Morresi. “Perugino’s technique in the Sistine Chapel: scientific investigations.” The Painting Technique of Pietro Vannucci, called Perugino: Proceedings of the LabS TECH Workshop. Eds. Brunetto Giovanni Brunetti, Claudio Seccaroni, and Antonio Sgamellotti. Pages 99-100

5 “Low Molecular Weight Varnishes.” Ed. Wendy Samet. Paintings Specialty Group Wiki, 1997. Web. Accessed June 4, 2017.

Madonna and Child by the Master of the Castello Nativity

In preparation for the Fitzwilliam Museum’s exhibition Madonnas and Miracles: Private Devotion in Renaissance Italy  paintings from the Fitzwilliam Museum collection came to the Hamilton Kerr Institute to be restored, including this beautiful and colourful panel  of the Madonna and Child by the Master of the Castello Nativity . When the painting arrived at the studio, the two main issues were a discoloured varnish layer and a very visible and irregular retouching covering the joint in the centre of the panel from top to bottom. This was my last project at the HKI; I left before I was able to finish it so Mary Kempski, Senior Paintings Conservator at the Institute, carried out the filling and retouching, bringing the treatment to completion.

Before treatment (© Titmus)
Before treatment (© Titmus)

The artist

Little is known about The Master of the Castello Nativity. He was an Italian painter, active in Florence and Prato in the mid-15th century, as well as a follower and possible pupil or collaborator of Filippo Lippi (c. 1406-69). He was nicknamed after another of his paintings of the Virgin adoring the Christ Child which originally came from Castello and is now kept in Florence [1] Around 30 paintings have been ascribed to him, a few of them show the same composition, as can be seen in the versions in the Uffizi, Florence and in the Huntington Library, California. All three versions have similar features: the kneeling Virgin praying with the Child in front, the star on the Virgin’s shoulder (probably Stella Maris), the veils covering the head and the hands of the Virgin, the gold decoration of the robes, the vegetation and the golden rays around the baby. The three paintings are of a considerable size and the one from the Fitzwilliam is the smallest.

The panel

The wooden panel (86.7 cm x 59.4 cm x 3.4 cm), most likely poplar, consists of two boards with the grain running vertically. At the back, the surface is irregular and shows tool marks from the initial preparation of the panel. The woodworm damage in the central section is severe and may well have weakened the panel internally causing it to split, a damage now visible from the front. The visible open channels from the woodworm activity on the vertical edges of the panel indicate that the edges have been cut off and the general size reduced at some point. The presence of six rectangular holes on the back could be related to a previous use of the panel, although their function is currently unknown.

Before treatment (© Titmus)
Before treatment (© Titmus)

The X-ray examination revealed the presence of an original piece of canvas covering the joint top to bottom and located under the ground and paint layers. It was common practice at this period to cover the defects and joints of the support with canvas soaked in glue before applying the ground layer. This would help level the surface and strengthen the weakest areas. Curiously, the canvas is missing just at the very bottom of the painting, but the reason for this is so far unknown.

X-ray (© Titmus)
X-ray (© Titmus)

The painting technique

The paint was in good condition, apart from extensive retouching along the split, as well as in the bottom corners. Based on the appearance and handling of the paint, the figures are most likely painted with tempera, while the landscape appears to be done in oil. The detailed areas of vegetation display very thick impasto. Upon ageing, the oil layers have become more transparent, allowing the previous layers of oil underneath to be seen, as is the case in the roses and the trees.

The gold, probably water-gilded, has been re-gilded in some areas. To recreate the volume of the curtain of the pavilion, dark glazes have been applied to the gold drapery, and some engraved marks (scoring and punching) were applied to give the gold different textural reflections.

The treatment

The work started with a full optical examination. Ultraviolet light revealed a discoloured varnish layer (probably a natural resin as it fluoresces in UV light, although not strongly) and a discoloured and irregular retouching covering the joint.

Joint before treatment (© González Juste)
Joint during treatment (© González Juste)

The painting was surface cleaned and the varnish removed. After removal of the top varnish layer, it was evident that there was still another varnish on the surface, in particular on the blue of the robe and the greens of the background.  A stronger solution was used in order to remove the last remnants of the varnish. The removal of the varnish layer also involved the removal of the majority of the overpaint, although there were remnants on the joint of the boards in the bottom right corner, and some across the red robe. These remnants were tough and probably older than the rest, possibly in a different medium.

The removal of old fills from the central join revealed at least three campaigns of filling and retouching, covering areas of the original, which had caused bulkiness across the join. The removal of the fills recovered hidden areas of original paint, which were in good condition.

Due to the uneven and dull quality of the flesh tones and the blue and red robes after varnish removal, these areas were examined more closely and samples were taken to try and identify the nature of this top grey layer. The study of the cross-sections suggests that the grey layer mainly consisted of an aged natural resin, too oxidised to lift off with free solvents.

The sample shows that the remaining varnish layer extended into a crack in the underlying original glaze, confirming that it was not original. The cross-section displayed below is a sample from the red robe after initial varnish removal. It shows the ground layer, probably gypsum with some black particles (1), a white pinkish imprimatura with a big red particle (2), a red glaze (3), and the varnish layer (4).


Cross-section from the red robe after initial varnish removal. (©González Juste)
Cross-section from the red robe after initial varnish removal. (©González Juste)

After several tests, it was decided that the painting could be greatly improved by removing this layer. As a result, this revealed brighter colours, such as the astonishing ultramarine blue robe and the delicacy of the veil covering the hands of the Virgin.

During dirt removal (© González Juste)
During dirt removal (© González Juste)

After full cleaning (© González Juste)
After full cleaning, before restoration (© González Juste)

The painting was brush-varnished and the losses were filled and retouched, and the area of damaged gilding in the halo was re-gilded.

After treatment (© Titmus)
After treatment (© Titmus)

Carlos González Juste, 2nd year intern (2014-2016)

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 been an intern in the Museo Nacional del Prado (Madrid), other Spanish institutions and the Hamilton Kerr Institute, Cambridge. He has participated in some traditional pigment making projects (“Cuttings: Mindful Hands. Masterpieces of Illumination” by Factum Arte among other projects). He is currently completing his Masters degree in the Escuela Superior de Conservación y Restauración de Bienes Culturales in Madrid and working as a private conservator.

To contact Carlos González Juste:


Madonna and Child, by Pietro da Orvieto

This 14th century Madonna and Child belongs to the Fitzwilliam Museum and is attributed to Pietro da Orvieto (1430-84). The painting came to the Hamilton Kerr Institute conservation studio in preparation for the Museum’s exhibition Madonnas and Miracles, which runs until 4th June 2017.

Condition of the Painting

While the painting was structurally sound, disfiguring and discoloured old retouchings were widespread across the paint surface, most prominent in the necks of the Virgin and Christ. The gilded frame and gilded background also presented a considerable amount of wear and abrasion, revealing the red bole and, in places, the underlying white gesso ground. When looking at the dark blue/black mantle of the Virgin in raking light, it was evident that considerable damage had occurred to this paint passage. The natural resin varnish layer had discoloured and the painting presented a dull greyish tone as the result of surface dirt accumulation and possibly the remains of a glair layer (an egg white varnish). During the treatment of this small painting interesting discoveries were made, such as the beautifully painted reverse, which we will share in this article.

How is the painting made?

This painting has been reconstructed by Anna Don, first year student at the Hamilton Kerr Institute. Her comprehensive step-by-step description includes many impressive photos, offering details that you might otherwise not see.

The support and frame

The painting is on a wooden panel (wood not identified) and is likely to be have been painted using egg tempera and oil glazes, mixed with dry pigments. The reverse of the painting was also painted using egg tempera, but with the exclusion of oil. The background of the painting is gilded, as are some of the details used for the Madonna’s robes. Its integral gilded frame is still present, attached to the front of the panel using nails, as can be seen in the X-radiograph image below. This is a rare find as frames of this type are often discarded having suffered too much damage over time through handling.

X-ray (© Titmus)
X-ray (© Titmus)

Paint layers

A white ground layer, probably of animal glue and gesso (untested) was applied to the back and front of the painting, as well as the frame. The infrared reflectography (IRR) image (see below) revealed the presence of underdrawing in certain areas of the composition, executed in a liquid medium using a brush. Around the figures, it is possible to make out incised lines etched into the gesso to indicate the areas that were to be gilded. The background and haloes are water-gilded in a conventional fashion and display a highly burnished appearance, whilst the decoration of the draperies was done using a mordant gilding technique. The haloes of the two figures were incised with fine circular lines with the use of a compass, while the decorations were made using punch tools.

Infrared (IRR) (© Titmus)

The flesh tones are distinctively Italian in terms of their build-up. The initial modelling was done using a green underpaint layer, known as verdaccio, which is traditionally made using a green earth pigment, as can be seen in the image of the Child below. This was followed by the application of the flesh tones. This layer was applied in fine, repetitive hatched brushstrokes, which is a common feature associated with the use of egg tempera.

The cleaning of the painting was carried out in several stages. The yellowed varnish, which extended from the painting onto the gilded background, as well as the old discoloured retouchings were removed. The upper image shows cleaning tests in the lower left corner, located in the Virgin’s headdress. This instantly made it easier to appreciate the original technique of the painting. It was then possible to remove an additional layer of grey dirt from the gilded background and from the frame mouldings, allowing the beautiful gilded background to shine brightly again.

A sample from the Virgin’s dark blue robe shows a build-up of two paint layers consisting of a greenish blue under layer with a darker, more intense blue upper layer, consisting of coarser pigment particles of azurite.

Sample from the dress, showing coarse azurite particles  (© van Dorst)
Sample from the dress, showing coarse azurite particles (© van Dorst)

The reverse

The painting’s biggest secret was revealed when the reverse was cleaned to uncover a colourful and decorative marble or porphyry imitation scheme, which is framed in a trompe-l’oeil stone moulding. This is a decorative motif commonly found in small scale, early Italian panel painting, but has been observed on a work by Albrecht Dürer. The painting on the reverse was completely obscured by the thick layer of dirt. To facilitate the painting of the straight lines that make up the grey borders, the artist incised the lines in the ground layer. The bright and fantastic colours of the reverse of this small devotional panel can once again be seen and admired.

Varnishing and retouching

It was decided to apply a protective and re-saturating varnish layer only to the painted areas on the front of the painting, but not to the gilded background, the gilded frame or to the reverse of the painting. This approach is in keeping with early Italian painting practice where the gilded areas, especially the water gilding, would have been left unvarnished. However, the painted areas on the front required a varnish layer in order to re-gain their saturation, whilst also providing an isolating layer between the original paint and the subsequent retouching.

After varnishing and filling (© van Dorst)The losses in the painted areas were toned with watercolour and glazed with Gamblin Conservation Colours. In the gilded areas, the losses were toned in a red colour, slightly lighter than the colour of the original bole.

After treatment, front (© Titmus)
After treatment, front (© Titmus)

Conclusion, come and see!

Written by Camille Polkownik and Sarah Bayliss, conservation treatment by Sven van Dorst.

About the author:
Sven Van Dorst graduated magna cum laude at the Artesis University College Antwerp (Belgium) in 2012, majoring in paintings conservation and restoration. The following two years, he worked on several projects at the Royal Museum of Fine Arts Antwerp and as a freelance conservator and painter. Sven completed a two-year postgraduate internship at the Hamilton Kerr Institute in 2016 and is currently working at The Phoebus Foundation (Belgium) as a conservator and researcher. Recently, he published essays on the technique of Antwerp flower painters in the Hamilton Kerr Bulletin and the Power Flower exhibition catalogue (Rockoxhuis Museum) as well as a piece on the 20th century Belgian artist Gustave van de Woestyne (catalogue: “Rooted, Painting Flanders”). In 2018, Sven will commence the treatment and research of the Dymphna altarpiece by Goswijn van der Weyden.
To contact Sven:


Uncovering vibrant colours through cleaning

Virgin and Child by Jos van Cleve is an oil painting on a wood panel that belongs to the Fitzwilliam Museum, Cambridge. The work was recently restored in preparation for the upcoming exhibition Madonnas and Miracles. The painting was in excellent condition prior to the conservation treatment, apart from a discoloured varnish that obscured the surface and dulled the vibrant colours used by the artist.

The Artist

Joos van Cleve (1464-1540) was a German-born painter active in Antwerp during the first half of the 16th century. His style can be described as a mixture of traditional Flemish and Italian Renaissance techniques. This particular painting, created between 1525-1529, is a good example of his hybrid style, as the traditional Flemish paint build-up and landscape contrasts with the Virgin’s sfumato shadows copied from paintings by Leonardo da Vinci. The subject of the Virgin and Child was very popular during this period and numerous versions of this composition exist by Joos van Cleve and his studio. The Fitzwilliam version has a peculiar detail, namely that the Virgin is smiling and her teeth are visible between her lips; a feature not usually seen in other representations of the subject.

 (click to enlarge photos)

The painting: construction and layers

The wooden support consists of two oak boards, quarter sawn and butt-joined using animal glue. The boards have not separated since the panel’s creation,  demonstrating the high quality of the wood and the expertise of the panel makers. We know that the panel had an original engaged frame, since a raised edge or ‘barb’ can be seen along the edge of the white chalk ground. This indicates that the panel was inserted into a frame immediately after its construction. Following this, the ground layer would have been added to the panel and the front of the frame simultaneously, leaving a build-up of ground along the inside of the frame.

A Flemish panel painting of this period would typically have been sized with a layer of animal glue on both sides, in order to limit the hygroscopic response of the wood. Following this, a ground layer would have been applied to the front of the panel in 1-2 layers and sanded to obtain a smooth finish. Northern grounds from the 15th-16th centuries are characterised by their use of animal glue and chalk (calcium carbonate), in contrast to the gypsum (calcium sulphate) grounds used by Italian artists during this period. The preparation of the ground was most likely carried out by professional panel makers, as opposed to the artist’s own workshop. Upon receiving the prepared panel, the artist would start by isolating the ground with a layer of oil (usually linseed or walnut). An initial design of the composition would then be drawn on top of the ground using a dry medium such as charcoal, pencil or chalk. In other cases wet media such as ink or diluted paint were used.

These preparatory designs or ‘underdrawings’ are often obscured entirely by subsequent applications of paint and are therefore invisible to the naked eye. However, the carbon content of traditional underdrawing media ensures that  they can be seen using infrared reflectography; an imaging technique that makes use of the longer wavelengths of infrared radiation to penetrate the upper paint layers and reveal the drawing below (Fig.). This method was used to uncover the detailed underdrawing used for the Fitzwilliam painting. Through scrutinising the intricate draughtsmanship that provided the basis for the composition Joos van Cleve’s mastery is fully revealed. A variety of lines were used to create an initial sketch for the composition, ranging from the curved outlines of the infant Christ’s flesh to the more angular and hatched marks used to indicate the folds of the Virgin’s robe.  In contrast to the detailed design reserved for the figures and drapery, there appears to be no underdrawing present for the landscape. It is possible Joos van Cleve had an apprentice in his workshop who filled in this part of the composition without the use of a preparatory design, as it was common to have students and trainees specialise in painting various parts of the painting.

Once the underdrawing was complete the paint was applied using very thin layers. The darker passages of the painting consist of several transparent layers painted on top of each other to give depth, exemplified by the folds of the Virgin’s robe and the darker tones of the landscape. Finally, the painting would have been finished through the application of a varnish, which most likely consisted of a natural resin dissolved in spirit or cooked in oil. The purpose of a varnish is to saturate the colours within the painting, creating a sense of depth, whilst also harmonising the various tones throughout the composition.

Conservation treatment

The initial treatment step consisted of surface cleaning to remove the thin layer of dust and grime that had accumulated on the painting’s surface over time. The varnish was then removed using organic solvents, which were chosen based on previous cleaning tests. The yellowed appearance of the varnish had a flattening effect on the shapes within the composition,  whilst also dulling the vibrancy of the colours. The removal of the varnish revealed a significant visual improvement for the painting. However, this was only the beginning. Underneath the varnish a grey layer of dirt continued to obscure the colours within the composition and its removal brought even more luminosity to the surface of the painting. In addition, a campaign of overpaint covered passages of old abrasions and losses, most notably in the red cloak of the Virgin and the tree on the right-hand side of the painting (these passages of overpaint are marked using red in the lower right photograph).

After the removal of the final dirt layer a very old, degraded layer of varnish remained on the cloth of honour behind the Virgin. It is possible that this localised coating was left by a previous restorer, perhaps due to the sensitivity of the paint in this area to organic solvents. The cloth, originally blue, had acquired a brownish-grey tint. Microscopic samples were taken from the painting to establish whether this layer was original or not. Examination of the samples in cross section indicated that the grey layer consisted of an old, oxidised varnish, as opposed to a pigment-containing glaze. The cross section samples further showed that the layer underneath contained blue and red pigment particles, creating an optical purple colour (see below). However, after cleaning the colour revealed showed a slightly more blue hue, most likely due to the photo-degradation and resultant fading of the organic red lake used for the optical mixture. 

Sample from the cloth of honour, normal light (©Polkownik)

Sample from the cloth of honour, ultraviolet light (©Polkownik)

Once it was clear that the uppermost degraded varnish layer was not pigmented, and therefore not considered original, we proceeded with the removal of this layer. The picture below shows the right side of the cloth after cleaning, revealing a vibrant purplish blue, while the left side is still covered by the discoloured varnish.

Fig. During cleaning, the right half of the cloth of honour has been cleaned (© Polkownik)

After the cleaning was complete, the painting was re-varnished using a modern synthetic resin that will not yellow upon ageing. The losses were filled using a water-soluble putty consisting of gelatin and chalk, and the fills were retouched using synthetic resin and pigments. All of the phases of the restoration, including varnish, fills and retouching are designed to be completely reversible, to facilitate their easy removal in the future. 

(Click to enlarge photos)

Although this painting came to the Hamilton Kerr Institute for minor restoration in preparation for an exhibition, the treatment served the purpose of uncovering the hidden  brightness of the colours, whilst also bringing forth the previously flattened volumes and shapes within the composition, most notably in the delicate sfumato of the Virgin’s face. The opportunity to restore such a beautiful and exceptionally well preserved painting was extremely enjoyable, whilst observing the mastery of Joos van Cleve in such detail helped broaden my understanding of 15th century Flemish painting technique.

Camille Polkownik – 2nd year Post Graduate Intern (2015-2017)


The Madonnas and Miracles exhibition (video)

About the Author

Ms Camille Polkownik graduated with a Master’s Degree in the Conservation and Restoration of Paintings in 2014, from the École nationale supérieure des arts visuels de La Cambre in Brussels (Belgium). 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 Cultural Heritage (KIK-IRPA, Belgium), the Royal Museums of Fine Art of Brussels (Belgium), the Museum of Fine Arts in Nice (France), at the Art Gallery of New South Wales (Sydney, Australia) and in private studios.

Her current research projects include the study of extenders added to Prussian Blue from 18th to 20th century in Europe, while matching and comparing paint samples to historic sources, and the characterisation of an unusual form of lead white called “Prismatic Lead White”.

To contact Camille Polkownik:

Sir Alfred East RA – Late 19th Century Landscape Painter

Self Portrait (©Kettering Art Gallery)

It is without a doubt that the artist Sir Alfred East (1844-1913), who was inspired by the Barbizon School, enjoyed the interest of the 19th century public.[1] The Times, for instance, referred to him on more than 500 occasions, and printed 11 bulletins describing his fluctuating condition in the month before he died.[2] Amongst various honours on a national and international scale bestowed on him, he was elected president of the Royal Society of British Artists (a post he held from 1906 until his death), received the status of Royal Academician (1913) and was awarded a knighthood by Edward VII (1910), but has since regrettably fallen into obscurity. Despite a slow start to his career, he was commissioned by the Fine Arts Society, to record the landscape of Japan over the course of a year. Subsequent travels he embarked on throughout his career to Europe and America yielded a vast collection of drawings, etchings and paintings in oil and watercolour. Before his death in 1913 East initiated the construction of the Alfred East Art Gallery in Kettering, Northamptonshire, that received a generous amount of his works.

Lake Bourget from Mont Revard, France (255 x 204 cm) before treatment, normal light (©Titmus)

Midland Meadows (162 x 218 cm) before treatment, normal light (©Titmus)

It is from this gallery that two of his paintings, namely Midland Meadows and Lake Bourget from Mont Revard, France, arrived to the Hamilton Kerr Institute for conservation treatment. The discoloured and disfiguring varnish layer on both paintings, was identified  as the main reason for the conservation treatment, although structurally sound, standing as a testament to his sound painting technique. Before the treatment of any painting, it is useful to conduct research about the artist and his painting technique, since it can often give an indication of the materials used by the artist. Nineteenth-century paintings in particular, frequently exhibit experimentation with media and layering that might give an unexpected and inconsistent response to the commonly used solvents for cleaning. Fortunately, in this case, the artist himself was rather keen on sharing his skill of landscape painting and how ‘to get the spirit of’ nature captured in a picture. [3] East wrote and published The Art of Landscape Painting in Oil Colour, his own guide to landscape painting, in 1906.[4] This manual explains his painting technique, and even mentions the pigments found on his palette, including the exact tube sizes. Thus it unsurprisingly formed an invaluable source for the treatment of the paintings.  

From his writings it appears that he adopted a well established three-stage-technique that makes use of an under-painting, another layer concerned with the correction of values, and a final stage for the addition of details; all painted with lean oil paint. During this process he practically repainted the entire canvas after the first layer and then proceeded to pick out isolated sections that required further reworking and detail. In doing so, some parts of the second layer that were not reworked in the last stage, and are now part of what is visible in the version we see today. An example of such an area is the fold over edge of Midland Meadows that shows trees reaching higher in the previous layer.

Midland Meadows, detail of first painting stage, normal light (©Straub)

Between the individual layers, East added medium (or binder) to saturate his lean oil paint layers – a process also known as ‘oiling out’. [5] Favoured particularly in the 19th century, this method used a cloth dipped in a medium of choice (- poppy seed oil for East), and rubbed into the dried paint, before the next paint layer followed. Some cross sections of the painting appear to show a layer that might be identified as such, with a characteristic absence of pigment and ultraviolet light quenching that is to be expected (not pictured in this article).  

Lake Bourget left: at the Royal Academy exhibition in 1900; middle: published in East’s The Art of Landscape Painting in Oil Colour in 1906; right: the painting in today’s state in ultra violet light (©Straub)

Not only is it possible to see proof of East’s described painting technique in his paintings, but Lake Bourget also reveals a significant compositional change by the artist that must have happened more than six years after it was first exhibited in 1900. Since the painting did not sell during the Royal Academy Exhibition, East may have been inclined to rethink his composition after a critic of his painting found that ‘his trees have had so much of the reality abstracted out of them that they cease to be interesting.’[6] An image of the same painting published in his manual in 1906 shows no changes. The first instance of alterations was registered by the Alfred East Art Gallery in Kettering who received the painting directly from the artist for their opening exhibition in 1913. There is little doubt that East’s reworkings happened before the painting arrived to the Gallery. In ultraviolet light it is also possible to ascertain some of the less visible passages he revisited, since they lie above the oiling out layer and therefore appear darker.

Lake Bourget, sensitive areas marked in yellow, normal light (©Titmus, Straub)

These areas also directly correspond to the passages that exhibited solvent sensitivity during cleaning. East’s described use of lean oil paint suggests that his mixtures were under-bound, meaning the pigment particles were not sufficiently coated with binding medium and therefore friable. Consequently the varnish covering sensitive areas was merely reduced and a thin layer was left in place.

Midland Meadows, during cleaning, normal light (©Straub)

Lake Bourget, during cleaning, normal light (©Straub)

Lake Bourget, detail varnish drip marks, normal light (©Straub)

After surface cleaning the decision to remove the discoloured varnish layer was supported by the fact that it reached into ageing cracks and losses, which means it is less likely that it was applied by the artist. Visually this layer also distracted from the composition with its drip marks in the sky.  In order to remove the varnish, small test areas in different coloured passages, were opened up to establish the best mixture of solvents for cleaning without affecting the paint layers. Usually the sensitivity of a paint layer corresponds to a specific colour or medium used in a passage. However, this was not the case in East’s paintings since the solubility appeared to be caused by underbound final paint dabs of varying colour. After cleaning an isolating synthetic resin varnish was applied, which is less prone to yellowing in the future than its natural counterpart, and the few existing minor losses were filled and retouched. To protect the paintings from vibration and environmental influences a sailcloth stretcher-bar-lining was attached. Moving and lifting such a large scale object, required continuous help from everyone in the studio, and framing was no exception to this. The gilt frame was given a few alterations to house the painting more securely (see the Weston Park in-situ post for more information) before the painting and frame were wrapped and transported back to the Alfred East Art Gallery in Kettering.

Midland Meadows, after treatment, normal light (©Titmus)

Lake Bourget from Mont Revard, France, after treatment, normal light ‎(©Titmus)

During the research for this project it was also possible to catch a glimpse of East’s meticulous character from his artist supplier account with Charles Roberson & Co, a 19th century colourman whose archive is housed at the Hamilton Kerr Institute. When he was sent a selection of brushes from Roberson, East rejected the majority; perhaps because they didn’t meet his standard.[7] He also appears to have repeatedly bought similar items from Roberson, suggesting that he may have had several specific colourman for different types of supplies.

Spending long hours in front of a painting the colours, lines and brushstrokes of the artist become very familiar. This direct contact with the painting was only furthered by the information that was gained about this artist and his technique, and made the treatment all the more interesting. Do visit the Alfred East Art Gallery in Kettering to see the actual paintings in their original exhibition space (due to their changing exhibitions it is best to inquire before a visit if the paintings are currently on display).

Michaela Straub, 3rd year Student


[1] and

[2]J Paul & M Kenneth, Alfred East Lyrical Landscape Painter, Bristol, 2009.

[3] J Paul & M Kenneth, p. 25.

[4] A East, The Art of Landscape Painting in Oil Colour, London, 1906. Further publications after his death include: E Bale & A East, Brush and Pencil Notes in Lanscape, London, 1914.; A East, H Cortazzi & Japan Society (London), A British Artist in Meiji Japan, Brighton, 1991.

[5] Oiling out is mentioned by several other artists such as George Frederic Watts in Watts, M. S. 1912. George Frederick Watts, London;  Gilman Harold (a new way of working that doesn’t involve oiling out); Lord Leighton (in a letter to Prof. Church he writes about using rectified petroleum instead of the normal process of oiling out) and is mentioned Leighton’s Painting process forms from the Royal Academy noting that for Daphnephoria he used Roberson’s medium for ‘rubbing in’.

[6]The Spectator no. 3750, 12 MAY 1900, p. 18

[7]Roberson Archive: MS 121-1993, p. 197; MS 313-1993, p. 88.

About the Author:

Currently in her third year studying easel painting conservation at the Hamilton Kerr Institute, Michaela Straub graduated from Aberystwyth University with a BA in Fine Art and Art History in 2012. She has undertaken internships in private studio’s, the Denkmalschutzamt in Germany and the Kunsthistorische Museum in Vienna.

To contact Michaela Straub:

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.

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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!

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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:

A Painting Transformed: From Pastoral Sunset to Burning Sodom

Once in a while, an artwork is not only aesthetically or structurally improved during treatment – it is completely transformed. This is the case with a privately owned painting treated during 2015 (Fig. 1).


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Figure 1 Before Treatment: Landscape with Ruins, Oil on canvas. (© Titmus)

Formerly attributed to Leonardo Coccorante (1680-1750), the ostensible subject of the painting corresponds with the eighteenth-century fashion for scenes of Roman ruins. The work depicts a pastoral landscape featuring crumbling ancient columns, with the skyline of a city in the distance highlighted by the setting sun.

When the work arrived at the Hamilton Kerr Institute, an incredibly thick, discolored varnish and heavy layer of grime obscured the scene. Examination with ultraviolet light did not reveal the extent of previous restoration. During cleaning, it started to become astonishingly clear that the entire sky and city in the distance had been overpainted. Many of the buildings in the distance had been completely invented, as was the sunset. Removing the previous restoration uncovered red and yellow shooting flames in the background – in fact, the entire city was ablaze. Additionally, the figures in the foreground had been altered. The blue-robed figure was not a shepherd, but rather an angel: the staff the figure carried was a later addition, and the figure’s large, white wings had been hidden by overpaint.

These discoveries led to the reassessment of the painting’s subject matter after treatment (Fig. 2). The most plausible identification of the narrative, given the newly manifest iconography, was that of the biblical account of Lot. The Book of Genesis describes how angels warned Lot of God’s imminent destruction of the cities of Sodom. This allowed Lot, his wife, and two of his four daughters to escape. However, the other two daughters and their husbands refused to flee and thus perished. In grief, Lot’s wife looked back towards the burning city and turned into a pillar of salt. Accordingly, in the painting, there is a small white figure in the background. The scene depicted in the painting follows this narrative remarkably closely, except that it pictures four young women (instead of only two daughters) at the far left. One possible explanation is that two of the women are Lot’s daughters, and two are angels leading them to safety; however, the worn condition of all four figures makes it difficult to distinguish any wings or otherwise characteristic features.

Figure 2 After Treatment, Landscape with Ruins, Oil on canvas (© Titmus)

The attribution to Leonardo Coccorante was also called into question because of the painting’s drastic alteration. While famous for his dramatic scenes of ruins, Coccorante is not known to have depicted biblical subjects. It was hoped that technical analysis would clarify the painting’s dating or region of origin. The work was analysed using X-ray Fluorescence Spectroscopy to detect the elements present within the paint and, therefore, infer the presence of various pigments. Dispersed pigment samples were also taken and examined with polarized light microscopy. The range of pigments identified unfortunately does not point to a specific geographic location or time period, but considering the painting’s other physical characteristics and stylistic attributes, the work most likely dates to the seventeenth or eighteenth century. This means that we cannot confirm or rule out Coccorante as the author and that other attributions should still be considered. François de Nomé (1593-1620) stands out as a particularly plausible alternative possibility: this French painter was based out of Rome and later Naples, and his dramatic scenes of ruins tend to deal with disastrous mythological or biblical narratives. In this sense, an attribution to this painter is perhaps more credible than that of Coccorante, though this text declines to make any definitive assignment.

Treating this painting was a rich experience and necessitated close consultation with the work’s owner. The treatment itself, the details of which are beyond the scope of this post, was challenging in that it required using various approaches to overpaint removal. Additionally, the heavily abraded state of the painting (which likely factored into the reason for overpainting in the first place) as well as a large loss in the lower right corner, necessitated difficult decisions regarding the appropriate extent of retouching. The transformation of the painting during treatment leaves lingering questions as to the work’s circumstances of creation and the identity of the painter.

One day, perhaps, these mysteries will be solved.

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: