Marat assassiné (Murdered Marat), one of the most famous masterpieces painted by Jacques-Louis Da... more Marat assassiné (Murdered Marat), one of the most famous masterpieces painted by Jacques-Louis David in 1793 has been investigated in situ by means of non-invasive and complementary analytical and imaging techniques. The overall material and technical information collected on this occasion led to important discoveries on the iconic picture of the French revolution. Following the identification of the palette used by David, we have shown the relationship between Marat assassiné and another David's painting. Features of David's artistic practice have been explained. Drastic changes in the final composition have been shown and explained based on scientific analysis and historical information. Finally we have formulated a hypothesis about how Marat assassiné could have been concealed.
The material study of ancient Egyptian paintings began with the advent of Egyptology during the 1... more The material study of ancient Egyptian paintings began with the advent of Egyptology during the 19th century. By the 1930s, a lot had already been sampled and described. The limited palette for example has been analysed from actual painted surfaces but also from pigments and painting tools retrieved on site. However, most of these studies took place in museums while the painted surfaces, preserved in funerary chapels and temples, remained somewhat estranged from this primary physical understanding. The artistic process has been also reconstructed, mainly from the information presented by unfinished monuments, showing surfaces at different stages of completion. A lot of this modern and theoretical reconstruction is, however, based on the usual archaeological guessing game that aims at filling the remaining blanks. Our interdisciplinary project has decided to experiment on-site with stateof-the-art portable analysis tools, avoiding any physical sampling, to see if our knowledge of the work of the ancient Egyptian painters and draughtsmen could be taken at a further stage, while based on physical quantification that could be seen as a stronger and more reliable foundation for a redefined scientific hypothesis. The use of XRF mapping has, for instance, been applied to a known case of correction by surface repaint, something that is supposedly rare in the ancient Egyptian formal artistic process, while another fully unexpected one was discovered during the analytic exploration of a royal representation. In both cases, the precise and readable imaging of the physical composition of the painted surface offers a renewed visual approach based of chemistry, that can be shared through a multiand interdisciplinary approach. However, this also leads to a more complex description of pigment mixtures that could have multiple meanings, where the practical often leads towards the symbolic, and from there hopefully to a renewed definition of the use of colours in complex sets of ancient Egyptian representations. At this stage, though the progress in this on-site material assessment of ancient works of art definitely means astonishing
La découverte de la Domus aux Bucranes, une maison tardo-républicaine remarquablement bien conser... more La découverte de la Domus aux Bucranes, une maison tardo-républicaine remarquablement bien conservée dans les couches les plus profondes du site de la Schola del Traiano à Ostia Antica , a permis le développement d’un projet de recherche interdisciplinaire portant sur le système décoratif de IIe style (pavements, enduits peints et reliefs de stuc) mis en œuvre à l’embouchure du Tibre, au cours du Ier s. av. J.-C. Outre son état de conservation exceptionnel, qu’il s’agisse d’éléments retrouvés in situ ou intégrés sous la forme de fragments dans les couches de remblais liés aux chantiers successifs, le système décoratif de la Domus aux Bucranes se distingue par la qualité des matériaux utilisés aussi bien que par la très grande maîtrise technique et artistique des ateliers alors sollicités. Fait remarquable : la fouille et l’étude de la stratigraphie de ce gisement a permis de restituer une séquence chronologique très précise concernant les phases de construction (60-50 av. J.-C.) et de destruction (30-20 av. J.-C.) de la domus, ainsi qu’une phase de restructuration intermédiaire (40-30 av. J.-C.) limitée à quelques pièces seulement. Si la destruction précoce de l’édifice a favorisé la conservation des pavements, ainsi que des enduits peints et des reliefs de stucs , la succession de deux phases de décoration durant le temps d’une même génération livre des informations de toute première importance quant à l’évolution du IIe style en Italie centrale, dans ses formes esthétiques aussi bien que dans ses compositions chimiques, au cours du deuxième tiers du Ier s. av. J.-C. De ce fait, en complément des traditionnelles études archéologiques et stylistiques, des analyses archéométriques ont été portées sur une partie significative du matériel sous enquête. Une telle démarche n’avait jamais encore été entreprise à Ostia Antica - sur des éléments en contexte aussi anciens - et les résultats obtenus, en cours d’interprétation , composeront une base de données de référence pour l’étude d’autres ensembles contemporains à Rome et ses environs. Nous en livrons ici les prémices, en limitant toutefois nos réflexions sur l’une des pièces restructurées et décorées durant la phase intermédiaire (40-30 av. J.-C.), l’« œcus des nains », ainsi nommée du fait de la nature des personnages mis en scène sur la frise peinte qui dominait la composition de cette pièce hors du commun.Peer reviewe
Painted in 1925 or 1926, over an older composition, La salle d'armes, is among the first ... more Painted in 1925 or 1926, over an older composition, La salle d'armes, is among the first Magritte's surrealist paintings. It is also one of the only four Magritte's using enamels reported in the René Magritte Catalog Raisonné. This paper presents the material and technical study conducted on this double painting. The complementary imaging and analytical methods applied for this purpose provided substantial information on both, the visible image and the hidden one. Concerning the latter, for instance, the obtained results permitted to iden- tify a cubo-futurist oil painting from the very early 1920s.
Artists started to experiment fluorescent colours shortly after the discovery of daylight pigment... more Artists started to experiment fluorescent colours shortly after the discovery of daylight pigments by the Switzer brothers in the 1940s. It is a new way of expression for painters from the 20th century such as Andy Warhol, Martial Raysse, Keith Haring and Pierre Alechinsky. More recently, artists from the 21st century use the daylight colours through new technics like aerosol spray paint [1]. It is well known that some fluorescent pigments are unstable. Indeed, phenomena of discolourations and fluorescence losses are often observed. The companies that provide this type of pigments kept secret the composition of their paints and aerosols. Moreover, knowledge of materials used by artists is so important for the history of the art of techniques but also for conservation issues. The aim of the study is to characterise and found identification markers from distinct fluorescent colours, from different manufacturers, using non-invasive methods namely Raman [2] and FT-IR spectroscopy, macro-XRF, X-ray diffraction and hyperspectral imaging. In a second step, after an artificial aging, the goal will be to observe how each pigment evolve to discern which are the most subject to the fading phenomenon. The final step of this study is to find the most optimal analytic strategy for the analysis of works of art, preserved at the Royal Museums of Fine Arts of Belgium, to identify pigments that are more susceptible to fade and enforce preventive conservation for this one. References [1] A. Colombini and C. Valageas, Technè, 38 (2013) 34-38 [2] W. Fremout, in: Conference paper from IRUG 11. (Boston, MA) (2014)Peer reviewe
1. Laboratoire d’Archéologie Moléculaire et Structurale, UMR 8220 CNRS – Université Pierre et Mar... more 1. Laboratoire d’Archéologie Moléculaire et Structurale, UMR 8220 CNRS – Université Pierre et Marie Curie, Paris, France. 2. S.A.R.L. Grotte de Rouffignac, France. 3. Musée National de Préhistoire, Les Eyzies-de-Tayac, France. 4. Instituto Internacional de Investigaciones Prehistóricas de Cantabria, Universidad de Cantabria, Santander, Spain. 5. Centre Européen d’Archéométrie, University of Liège, Belgium.
One of the two missing canvases from L’évidence éternelle of 1954, the one of the feet, has been ... more One of the two missing canvases from L’évidence éternelle of 1954, the one of the feet, has been discovered beneath a small woman portrait painted in 1958, La toile de Pénélope. Indeed, the underlying woman’s feet revealed through the IRR and XRR images leave little doubt about the identity of the hidden composition. All the more so as the canvas dimensions perfectly match with the format ascribed to the feet part in the diagram Magritte made of the 1954 variant of L’évidence éternelle. This paper presents the main results of the material study conducted on La toile de Pénélope by means of non-invasive and complementary imaging and analytical techniques. Furthermore, it proposes a virtual colorized reconstruction of the hidden picture, built on the basis of the XRR and IRR images, the elemental information provided by the MA-XRF analysis, the Raman results and the microscope examination of the painting surface.
Actuellement, cinq formes de bleu de phtalocyanine de cuivre sont utilisees comme pigments artist... more Actuellement, cinq formes de bleu de phtalocyanine de cuivre sont utilisees comme pigments artistiques: PB15, :1, :2, :3, :4, et :6. PB15 qui correspond a la forme la plus utilisee apres PB15 :3 est sujette a la cristallisation. Ce phenomene qui s’observe plus particulierement en presence de solvants aromatiques entraine un glissement de teinte du bleu vers le vert et une perte du pouvoir couvrant du pigment. Or, l’usage de solvants aromatiques dans le champ de la conservation-restauration de peintures de chevalet est relativement commun. Citons par exemple, le toluene et les xylenes qui entrent dans la composition de certains melanges de solvants, de certains types vernis (Laropal A81) et d’adhesifs (Beva 371). C'est pourquoi il est necessaire d’effectuer une recherche de maniere a determiner si les conditions d’utilisation des solvants aromatiques en conservation-restauration provoquent la cristallisation de PB15. Dans cet article, les premiers resultats obtenus sur des echantillons de PB15, :1, :2, :3, :4 et :6 en poudre sont presentes. Les cinq formes susmentionnees ont ete examinees sous microscope polarisant et analysees par spectroscopie infrarouge a transformee de Fourier et diffraction de rayons X, avant et apres leur immersion dans les solvants aromatiques, de facon a pouvoir comparer les proprietes optiques et chimiques.
Marat assassiné (Murdered Marat), one of the most famous masterpieces painted by Jacques-Louis Da... more Marat assassiné (Murdered Marat), one of the most famous masterpieces painted by Jacques-Louis David in 1793 has been investigated in situ by means of non-invasive and complementary analytical and imaging techniques. The overall material and technical information collected on this occasion led to important discoveries on the iconic picture of the French revolution. Following the identification of the palette used by David, we have shown the relationship between Marat assassiné and another David's painting. Features of David's artistic practice have been explained. Drastic changes in the final composition have been shown and explained based on scientific analysis and historical information. Finally we have formulated a hypothesis about how Marat assassiné could have been concealed.
The material study of ancient Egyptian paintings began with the advent of Egyptology during the 1... more The material study of ancient Egyptian paintings began with the advent of Egyptology during the 19th century. By the 1930s, a lot had already been sampled and described. The limited palette for example has been analysed from actual painted surfaces but also from pigments and painting tools retrieved on site. However, most of these studies took place in museums while the painted surfaces, preserved in funerary chapels and temples, remained somewhat estranged from this primary physical understanding. The artistic process has been also reconstructed, mainly from the information presented by unfinished monuments, showing surfaces at different stages of completion. A lot of this modern and theoretical reconstruction is, however, based on the usual archaeological guessing game that aims at filling the remaining blanks. Our interdisciplinary project has decided to experiment on-site with stateof-the-art portable analysis tools, avoiding any physical sampling, to see if our knowledge of the work of the ancient Egyptian painters and draughtsmen could be taken at a further stage, while based on physical quantification that could be seen as a stronger and more reliable foundation for a redefined scientific hypothesis. The use of XRF mapping has, for instance, been applied to a known case of correction by surface repaint, something that is supposedly rare in the ancient Egyptian formal artistic process, while another fully unexpected one was discovered during the analytic exploration of a royal representation. In both cases, the precise and readable imaging of the physical composition of the painted surface offers a renewed visual approach based of chemistry, that can be shared through a multiand interdisciplinary approach. However, this also leads to a more complex description of pigment mixtures that could have multiple meanings, where the practical often leads towards the symbolic, and from there hopefully to a renewed definition of the use of colours in complex sets of ancient Egyptian representations. At this stage, though the progress in this on-site material assessment of ancient works of art definitely means astonishing
La découverte de la Domus aux Bucranes, une maison tardo-républicaine remarquablement bien conser... more La découverte de la Domus aux Bucranes, une maison tardo-républicaine remarquablement bien conservée dans les couches les plus profondes du site de la Schola del Traiano à Ostia Antica , a permis le développement d’un projet de recherche interdisciplinaire portant sur le système décoratif de IIe style (pavements, enduits peints et reliefs de stuc) mis en œuvre à l’embouchure du Tibre, au cours du Ier s. av. J.-C. Outre son état de conservation exceptionnel, qu’il s’agisse d’éléments retrouvés in situ ou intégrés sous la forme de fragments dans les couches de remblais liés aux chantiers successifs, le système décoratif de la Domus aux Bucranes se distingue par la qualité des matériaux utilisés aussi bien que par la très grande maîtrise technique et artistique des ateliers alors sollicités. Fait remarquable : la fouille et l’étude de la stratigraphie de ce gisement a permis de restituer une séquence chronologique très précise concernant les phases de construction (60-50 av. J.-C.) et de destruction (30-20 av. J.-C.) de la domus, ainsi qu’une phase de restructuration intermédiaire (40-30 av. J.-C.) limitée à quelques pièces seulement. Si la destruction précoce de l’édifice a favorisé la conservation des pavements, ainsi que des enduits peints et des reliefs de stucs , la succession de deux phases de décoration durant le temps d’une même génération livre des informations de toute première importance quant à l’évolution du IIe style en Italie centrale, dans ses formes esthétiques aussi bien que dans ses compositions chimiques, au cours du deuxième tiers du Ier s. av. J.-C. De ce fait, en complément des traditionnelles études archéologiques et stylistiques, des analyses archéométriques ont été portées sur une partie significative du matériel sous enquête. Une telle démarche n’avait jamais encore été entreprise à Ostia Antica - sur des éléments en contexte aussi anciens - et les résultats obtenus, en cours d’interprétation , composeront une base de données de référence pour l’étude d’autres ensembles contemporains à Rome et ses environs. Nous en livrons ici les prémices, en limitant toutefois nos réflexions sur l’une des pièces restructurées et décorées durant la phase intermédiaire (40-30 av. J.-C.), l’« œcus des nains », ainsi nommée du fait de la nature des personnages mis en scène sur la frise peinte qui dominait la composition de cette pièce hors du commun.Peer reviewe
Painted in 1925 or 1926, over an older composition, La salle d'armes, is among the first ... more Painted in 1925 or 1926, over an older composition, La salle d'armes, is among the first Magritte's surrealist paintings. It is also one of the only four Magritte's using enamels reported in the René Magritte Catalog Raisonné. This paper presents the material and technical study conducted on this double painting. The complementary imaging and analytical methods applied for this purpose provided substantial information on both, the visible image and the hidden one. Concerning the latter, for instance, the obtained results permitted to iden- tify a cubo-futurist oil painting from the very early 1920s.
Artists started to experiment fluorescent colours shortly after the discovery of daylight pigment... more Artists started to experiment fluorescent colours shortly after the discovery of daylight pigments by the Switzer brothers in the 1940s. It is a new way of expression for painters from the 20th century such as Andy Warhol, Martial Raysse, Keith Haring and Pierre Alechinsky. More recently, artists from the 21st century use the daylight colours through new technics like aerosol spray paint [1]. It is well known that some fluorescent pigments are unstable. Indeed, phenomena of discolourations and fluorescence losses are often observed. The companies that provide this type of pigments kept secret the composition of their paints and aerosols. Moreover, knowledge of materials used by artists is so important for the history of the art of techniques but also for conservation issues. The aim of the study is to characterise and found identification markers from distinct fluorescent colours, from different manufacturers, using non-invasive methods namely Raman [2] and FT-IR spectroscopy, macro-XRF, X-ray diffraction and hyperspectral imaging. In a second step, after an artificial aging, the goal will be to observe how each pigment evolve to discern which are the most subject to the fading phenomenon. The final step of this study is to find the most optimal analytic strategy for the analysis of works of art, preserved at the Royal Museums of Fine Arts of Belgium, to identify pigments that are more susceptible to fade and enforce preventive conservation for this one. References [1] A. Colombini and C. Valageas, Technè, 38 (2013) 34-38 [2] W. Fremout, in: Conference paper from IRUG 11. (Boston, MA) (2014)Peer reviewe
1. Laboratoire d’Archéologie Moléculaire et Structurale, UMR 8220 CNRS – Université Pierre et Mar... more 1. Laboratoire d’Archéologie Moléculaire et Structurale, UMR 8220 CNRS – Université Pierre et Marie Curie, Paris, France. 2. S.A.R.L. Grotte de Rouffignac, France. 3. Musée National de Préhistoire, Les Eyzies-de-Tayac, France. 4. Instituto Internacional de Investigaciones Prehistóricas de Cantabria, Universidad de Cantabria, Santander, Spain. 5. Centre Européen d’Archéométrie, University of Liège, Belgium.
One of the two missing canvases from L’évidence éternelle of 1954, the one of the feet, has been ... more One of the two missing canvases from L’évidence éternelle of 1954, the one of the feet, has been discovered beneath a small woman portrait painted in 1958, La toile de Pénélope. Indeed, the underlying woman’s feet revealed through the IRR and XRR images leave little doubt about the identity of the hidden composition. All the more so as the canvas dimensions perfectly match with the format ascribed to the feet part in the diagram Magritte made of the 1954 variant of L’évidence éternelle. This paper presents the main results of the material study conducted on La toile de Pénélope by means of non-invasive and complementary imaging and analytical techniques. Furthermore, it proposes a virtual colorized reconstruction of the hidden picture, built on the basis of the XRR and IRR images, the elemental information provided by the MA-XRF analysis, the Raman results and the microscope examination of the painting surface.
Actuellement, cinq formes de bleu de phtalocyanine de cuivre sont utilisees comme pigments artist... more Actuellement, cinq formes de bleu de phtalocyanine de cuivre sont utilisees comme pigments artistiques: PB15, :1, :2, :3, :4, et :6. PB15 qui correspond a la forme la plus utilisee apres PB15 :3 est sujette a la cristallisation. Ce phenomene qui s’observe plus particulierement en presence de solvants aromatiques entraine un glissement de teinte du bleu vers le vert et une perte du pouvoir couvrant du pigment. Or, l’usage de solvants aromatiques dans le champ de la conservation-restauration de peintures de chevalet est relativement commun. Citons par exemple, le toluene et les xylenes qui entrent dans la composition de certains melanges de solvants, de certains types vernis (Laropal A81) et d’adhesifs (Beva 371). C'est pourquoi il est necessaire d’effectuer une recherche de maniere a determiner si les conditions d’utilisation des solvants aromatiques en conservation-restauration provoquent la cristallisation de PB15. Dans cet article, les premiers resultats obtenus sur des echantillons de PB15, :1, :2, :3, :4 et :6 en poudre sont presentes. Les cinq formes susmentionnees ont ete examinees sous microscope polarisant et analysees par spectroscopie infrarouge a transformee de Fourier et diffraction de rayons X, avant et apres leur immersion dans les solvants aromatiques, de facon a pouvoir comparer les proprietes optiques et chimiques.
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Papers by Catherine Defeyt