Category: Treatment

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.

Cleaning

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.

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.

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).

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.

Dendrochronology

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.

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).

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. 

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

Cross-section

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).

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.

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.

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.

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: camille.polkownik@gmail.com

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

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.

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.

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.

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.

Treatment

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.

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).

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: rayner.kari.s@gmail.com

Notes

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. http://www.conservation-wiki.com/wiki/IV._Low_Molecular_Weight_Varnishes

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.

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-15^th 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.

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.

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.

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).

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.

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

Carlos González Juste, 2^nd 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: cgjuste@gmail.com