Articles by Nathalie Balcar
Technè
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Polymer Degradation and Stability, 2018
Polyurethane (PUR) ester foams are found in 20th century museum collections in a variety of artwo... more Polyurethane (PUR) ester foams are found in 20th century museum collections in a variety of artworks and objects. Unfortunately PUR ester foams are prone to degradation, and present e among other plastic materials e important conservation issues. They are very sensitive to moisture, and their hy-drolysis leads to several degradation processes such as yellowing and embrittlement, drastically changing the artwork aspect and materiality. Few researches were conducted on the consolidation of PUR ester foams. In this paper, a curative treatment that should limit the hydrolysis of the degraded PUR foams, and that mechanically consolidate the foams' structure is presented. This work focuses on the innovative use of alkoxysilanes mixtures and on their application modes on foam samples. Different binary mixtures of OTMS (n-octyltriethoxysilane, hydrophobic and trifunctional) and AMDES (3-aminopropylmethyldiethoxysilane, hydrophilic and bifunctional) in various proportions were tested. The kinetic evolution of their polycondensation using spectral decomposition of FTIR spectra revealed that OTMS does not react with atmospheric water vapor and that the presence of an amine (AMDES) is required to initiate its polycondensation. This result justifies the use of a mixture of both siloxanes. The different treatments were then applied on artificially degraded PUR ester foams using concentration of 2.5% and 10% of alkoxysilanes in HMDS (hexamethyldisiloxane, solvent). The treatment was applied by pouring the solution over the samples and resulted in a homogeneous impreg-nation of the foams, whereas vaporization modes were unsuccessful regarding the penetration of the treatment in the foam cells. The hydrophilicity of the treatments was characterized using water contact angle measurements and it appears that at least 25% of hydrophobic OTMS in the mixture is needed to decrease the wettability of the samples, in order to avoid further hydrolysis. The reinforcement properties were studied using mechanical tests, and resulted in a need of a solution of 10% (in HMDS) for an acceptable reinforcement. Finally, colorimetric measurements showed that the visual aspect of the degraded samples was improved with the treatment.
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TECHNE, 46, 2018
Among the objects present in collections of 20th-century art, those made of ester polyurethane fo... more Among the objects present in collections of 20th-century art, those made of ester polyurethane foam pose serious conservation problems, mainly related to the loss of their mechanical properties due to their breakdown through hydrolysis. The aim of this work was to develop and test a mix of polymers from the polysiloxanes family which would enable ester polyurethane foams to be stabilised: a mixture based on hydrophilic AMDES (3-aminopropylmethyldiethoxysilane) and hydrophobic OTMS (octyltrimethoxysilane). The application of this mixture in different manners intended to be transposable to real objects was tested on polyurethane foam samples by national heritage restors.
Parmi les objets présents dans les collections d’art du XXe siècle, ceux réalisés en mousse de polyuréthane (PUR) ester posent de sévères problèmes de conservation liés principalement à la perte de leurs propriétés mécaniques due à leur dégradation par hydrolyse. Le but de ce travail a été de développer et tester un mélange de polymères de la famille des polysiloxanes qui permettrait de stabiliser les mousses PUR ester : un mélange à base d’AMDES (3-aminopropylmethyldiethoxysilane), hydrophile, et d’OTMS (octyltriméthoxysilane), hydrophobe. L’application de ce mélange suivant différents modes se voulant transposables à de véritables objets a été testée sur des échantillons de mousse PUR ester par des restaurateurs du patrimoine.
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TECHNE, 2018
Plasticized polyvinyl chloride is a synthetic polymer, widely used from the mid-20th century unti... more Plasticized polyvinyl chloride is a synthetic polymer, widely used from the mid-20th century until today in the production of artworks and artefacts. Its condition is often mediocre owing to the migration of plasticizers. The study of the impact of cleaning and conditioning on the evolution of naturally ageing PVCs in a museum environment has enabled us to envisage optimum conditions for preventive conservation so as to mitigate the degradation process.
Le polychlorure de vinyle plastifié est un polymère synthétique, largement utilisé depuis le milieu du XXe siècle et jusqu’à nos jours, pour la production d’œuvres d’art et d’objets.Son état de conservation est souvent médiocre en raison de la migration des plastifiants. L’étude de l’impact du nettoyage et du mode de conditionnement de PVC vieillis naturellement en environnement muséal sur leur évolution permet d’envisager des conditions de conservation préventives et curatives optimales afin d’en limiter les dégradations.
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Applied Physics A, 2015
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Studies in Conservation, 2016
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This book is not an art picture book although it contains pictures of works of art, and this is n... more This book is not an art picture book although it contains pictures of works of art, and this is not a scientific treatise although it does include chemical formulae! This book is about both art and science and represents a significant milestone in the journey towards understanding the issues associated with plastics in museum collections, and equally importantly, it helps point the way forward for future work. Just as plastics are relatively modern materials, so the science of their degradation is a relatively young science and the understanding of how we should care for our plastic heritage is still in its infancy. This book is created for the conservation community interested in the preservation of art and design works that happen to be made out of a wide variety of plastic formulations. It gathers a bulk of knowledge that is a record of the latest conservation science and technology as applied to plastic works of art, gained during the POPART project – the Preservation Of Plastic...
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Preservation of Plastic Artefacts in Museum Collections, pp 61-69, Mar 2012
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Technè n° 38, 2013, pp 13-16
Le département Restauration du C2RMF a fait l’acquisition en 2011 d’un spectromètre infrarouge po... more Le département Restauration du C2RMF a fait l’acquisition en 2011 d’un spectromètre infrarouge portable qui est dédié à l’identification des plastiques. Il est donc à présent possible de proposer aux musées une étude de leur collection in situ et de manière non invasive dans un contexte de conservation préventive ou d’étude préalable à la restauration. Plusieurs campagnes d’analyse sur différentes typologies d’objets ont permis d’apprécier le potentiel et les limites de cette méthode d’analyse.
In 2011, the C2RMF Restoration Department acquired a portable infrared spectrometer, which is used to identify plastics. It is therefore now possible to offer museums an in-situ, non-invasive analysis of their artefacts within the context of preventive conservation or as a preliminary study to restoration. Several analytical projects on different types of objects have enabled us to measure the potential and limits of this method of analysis."
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Journal of Cultural Heritage, Volume 14, Issue 3, Pages 238-247, Jan 1, 2012
In recent years, plastics are designated as a source of indoor pollution and particular attention... more In recent years, plastics are designated as a source of indoor pollution and particular attention has thus been devoted to the identification of emitting low molecular weight compounds. Headspace-solid phase microextraction-gas chromatography coupled with mass spectrometry (HS-SPME-GC/MS) has been already successfully applied for screening emissions from synthetic materials. This analytical tool being also non-invasive, it has been already successfully applied in the field of cultural heritage science for the identification of volatile organic compounds (VOCs) emitted from various museum objects made of natural materials. In this research, we aimed at assessing the use of HS-SPME-GC/MS as an in situ non-invasive analytical tool for a better knowledge of the volatile organic compounds emitted by plastics in collections. The possibility of characterizing plastics based on their emission signatures was also evaluated. Twelve new standard plastic samples, belonging to seven main polymer families widely present in museum collections as well as three naturally aged museum objects, were investigated. In this paper, we provide a survey of the VOCs emitted, and the use of HS-SPME-GC/MS for identifying volatile marker compounds, degradation products, additives, and monomer residues of the plastic synthesis is evaluated. More than 200 different VOCs were identified from the new standard samples. Two categories of VOCs were distinguished: “non-specific” and “specific” ones. We showed that based on the “specific” VOCs, it was possible to identify the nature of the polymeric matrix itself or at least to unambiguously distinguish a plastic by family. Emissions from the museum objects were then characterised, and main volatile degradation compounds considered as degradation markers of the natural deterioration of polymeric matrices, were identified. This identification procedure could be further exploited for the characterization of VOCs emitted by objects made of multiple synthetic polymers. Complementary to other techniques, this analytical tool is an interesting way to assess the risk for the objects stored in the vicinity of emitting plastics
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13è Journées de la SFIIC, art d’aujourd’hui patrimoine de demain, pp 146-155, 2009
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Preservation of Plastic Artefacts in Museum Collections, pp 302-308, Mar 2012
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In Book. ICOM-CC 16th triennial conference Lisbon 19-23 September 2011: preprints, Sep 1, 2011
La rénovation des salles du XVIIIe siècle du département des Objets d’art au musée du Louvre a re... more La rénovation des salles du XVIIIe siècle du département des Objets d’art au musée du Louvre a représenté une occasion unique d’étudier et de restaurer un ensemble majeur de meubles Boulle. Les départements Recherche et Conservation-restauration du Centre de recherche et de restauration des musées de France (C2RMF) ont été chargés de superviser une équipe multidisciplinaire de restaurateurs, de scientifiques et de conservateurs, ainsi que des stagiaires, provenant de différentes institutions ou du privé. L’examen approfondi du mobilier et l’étude des rares comptes-rendus existants sur les précédents traitements de restauration nous ont permis de mieux comprendre leur état de préservation et d’évaluer leur authenticité. Bien qu’ils aient été continuellement – et parfois lourdement – restaurés depuis leur fabrication, et malgré le nombre de publications consacrées à ces questions au cours des vingt dernières années, aucune réponse satisfaisante n’a été apportée quant au traitement du mobilier Boulle. La recherche sur les principaux problèmes liés au nettoyage, au collage et à la protection s’est donc poursuivie.
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Techné 49, 2020
La récente campagne de restauration, au sein des ateliers
du C2RMF, d’un ensemble de meubles du m... more La récente campagne de restauration, au sein des ateliers
du C2RMF, d’un ensemble de meubles du musée du Louvre
décorés de marqueterie Boulle a été l’occasion de s’intéresser aux
pigments utilisés pour mettre en couleur les parties en corne et en
écaille de tortue. Cette étude conduite exclusivement à partir de
micro-prélèvements a confirmé la technicité complexe de la mise en
oeuvre de ces couleurs.
Undertaken in the C2RMF workshops, the recent
restoration of pieces of furniture decorated with Boulle marquetry
from the Louvre, provided an occasion to examine the pigments
used to add colour to the parts made of horn and turtle shell. This
study, based on micro-samples alone, confirmed the complex
techniques involved in the application of these colours.
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Techné 49, 2020
La réflexion sur le remplacement du traditionnel vernis à
la gomme-laque par une autre couche de ... more La réflexion sur le remplacement du traditionnel vernis à
la gomme-laque par une autre couche de finition a débuté en 2002
au C2RMF. Elle avait pour but de mettre en évidence les éventuelles
relations entre dégradation et composition du vernis, d’évaluer le
rôle de protection sur les bois de vernis de compositions différentes
et enfin d’étudier l’influence de la lumière sur l’évolution dans le
temps des bois ainsi vernis. L’expérimentation mise en oeuvre s’est
focalisée sur un vernis décrit dans L’Art du menuisier-ébéniste
publié par André-Jacob Roubo en 1774. Plusieurs tests de mesure
d’épaisseur, d’apparence et de propriété mécanique ont été réalisés
sur des éprouvettes de bois de placage recouverts du vernis
sélectionné. Les résultats encourageants de son effet protecteur à la
photo-oxydation et à l’oxygène de l’air ont permis de mettre en place
un protocole en vue de son application comme protection de surface
pour le mobilier en marqueterie de métal du musée du Louvre.
Reflection on replacing traditional shellac varnishes
with another finish began in 2002 at the C2RMF. The aim was to
highlight the possible relationship between deterioration and the
composition of the varnish, to assess the role played by protective
coatings made of different ingredients on wood and, lastly, to study
the long-term effects of light on woods thus varnished. The
experiments conducted focused on a varnish described in L’Art du
menuisier-ébéniste, published by André-Jacob Roubo in 1774.
Several tests to measure thickness, appearance and mechanical
properties were carried out on samples of veneer coated in the
selected varnish. The encouraging results of its resistance to photooxidation
and the oxygen in the air enabled us to establish a
protocol for applying it to protect the surface of the metal marquetry
furniture now in the Louvre.
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Techné 49, 2020
La restauration d’une oeuvre de mobilier offre
l’opportunité de s’intéresser à la colle qui assur... more La restauration d’une oeuvre de mobilier offre
l’opportunité de s’intéresser à la colle qui assure le maintien des
différents éléments sur la structure en bois. Une nouvelle technique
d’investigation des colles, jusque-là absente des laboratoires
français dédiés à l’étude du patrimoine, a été évaluée et validée
pour connaître l’origine animale de ce matériau
The restoration of a piece of furniture offers researchers
a chance to study the glue used to hold the different parts of the
wooden structure together. A new investigative method of
determining the adhesive used, previously unavailable in French
laboratories reserved for cultural heritage studies, was tested and
validated. It confirmed the animal origin of this glue.
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Technè n° 38, 2013, pp 112-117
Dans le cadre de la rénovation des salles du XVIIIe siècle du département des Objets d’art, le mu... more Dans le cadre de la rénovation des salles du XVIIIe siècle du département des Objets d’art, le musée du Louvre a fait appel au C2RMF afin de restaurer les boiseries sculptées de l’hôtel particulier Le Bas de Montargis, construit par Jules Hardouin- Mansart vers 1705. La restauration, qui a nécessité plus d’un an de travail, a porté aussi bien sur la structure que sur la surface dorée des boiseries : la menuiserie a été révisée et la dorure a fait l’objet d’un programme complexe de dégagement, nettoyage et harmonisation. L’ampleur de l’étude préalable et de la restauration relève d’une approche minutieuse qui s’inscrit dans l’évolution du regard posé sur les arts décoratifs et les grands décors.
As part of the renovation programme for the 18th-century rooms of the Department of Decorative Arts, the Louvre asked the C2RMF to restore the carved wood decoration from the mansion called Le Bas de Montargis, built by Jules Hardouin-Mansart circa 1705. The restoration, which required over a year’s work, involved both the structure and the surface of the gilded decorative woodwork: the panelling was restored and the gilding underwent a complex process of removal, cleaning and harmonization. The scale of the preliminary study and restoration reflects a meticulousness that shows the changes in attitude towards decorative arts and large decorative schemes""
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TECHNÈ n° 36, 2012, pp 118-125, Nov 1, 2012
Au XVIIe siècle, au Mans et dans tout le Maine, est apparue une importante production de sculptur... more Au XVIIe siècle, au Mans et dans tout le Maine, est apparue une importante production de sculptures en terre cuite. Alors que la pierre et le bois sont prédominants en France à cette époque, les sculpteurs manceaux se démarquent par l’emploi d’une technique peut-être liée à la venue d’artistes italiens. L’étude de la polychromie de douze sculptures a permis de détecter des techniques de mise en oeuvre, qui diffèrent des pratiques habituelles de l’époque, avec notamment l’utilisation d’un matériau local, la roche dolomitique, comme préparation, ou encore la présence de sous-couche au blanc de plomb sous cette dernière et sous des décors a sgraffito. Une gamme de bleus étendue a également été mise en évidence. Un de ces pigments se démarque particulièrement. Il s’agit d’un bleu au cuivre, une azurite de synthèse, dont le faciès des grains, observé à fort grossissement, est très spécifique. L’emploi d’un tel pigment est vraisemblablement à mettre en relation avec l’industrialisation et la commercialisation en Angleterre du bleu verditer. Cette étude permet ainsi d’avoir une première vision du travail d’artistes qui semblent avoir innové par rapport aux techniques traditionnelles.
In the 17th century, Le Mans and the entire Maine region became an important production area for terracotta sculpture. While stone and wood were predominant in France at this time, sculptors in Le Mans were distinguished by their use of a technique possibly related to the arrival of Italian artists. The examination of the polychromy on twelve sculptures enabled us to detect the use of techniques unlike those usually practised in this period, namely a primer based on a local material, dolomite rock, and the presence of a white lead-based undercoat under this primer and the sgraffito decoration. A wide range of blues were also brought to light. One of these pigments stood out in particular. It was a copper blue, a synthetic azurite, whose pigment granules, when magnified, have a very distinctive appearance. The use of such a pigment can very probably be related to the industrialization and sale in England of verditer blue. This study thus provided initial insight into the work of artists who seemed to have innovated as opposed to using traditional techniques.""""
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Techné, no. 32, 2010, pp. 71-80
Dans le cadre de recherches interdisciplinaires sur l’histoire de la restauration des vases grecs... more Dans le cadre de recherches interdisciplinaires sur l’histoire de la restauration des vases grecs, l’étude scientifique d’une soixantaine d’objets conservés dans des musées français a été menée au C2RMF. Après avoir exposé les méthodes d’examen et d’analyse employées, l’article traite des techniques picturales mises en oeuvre par les praticiens d’un art de la restauration illusionniste des vases dont Naples a été la capitale incontestée, à la fin du XVIII e et au début du XIXe siècle. Il s’attache enfin à certaines particularités de la manière de Brocchi restaurateur, telles qu’on a pu les mettre en évidence sur les deux cratères apuliens du Louvre K 66 et K 67
Mots-clés. Vase grec, étude scientifique, restauration illusionniste, Naples, Paris, XVIII e siècle, XIX e siècle, vernis, pigments, gomme laque, Brocchi.
Within the framework of an interdisciplinary research programme on the restoration history of Greek vases, a scientific investigation of about sixty objects from French museums was carried out at the C2RMF. After presenting the methods of examination and analysis used, the article describes the pictorial techniques employed by craftsmen specializing in the illusionist restoration of vases, for which Naples was the undisputed capital, in the late 18th and early 19th centuries. Lastly it highlights certain stylistic characteristics of the restorer Luigi Brocchi, as can be seen on the Louvre’s two Apulian kraters, K 66 and K 67
Keywords : Greek vase, scientific investigation, illusionist restoration, Naples, Paris, 18th century, 19th century, varnish, pigments, shellac, Brocchi
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Technè n°17, Jan 1, 2003
... Author: Bourgeois, Brigitte; Balcar, Nathalie; Borel, Thierry; Denoyelle, Martine; Lacambre, ... more ... Author: Bourgeois, Brigitte; Balcar, Nathalie; Borel, Thierry; Denoyelle, Martine; Lacambre, Geneviève; Merlin, Christine Title Article/Chapter: "Autour d'une collection d'artiste: la re-restauration de vases antiques du musée Gustave Moreau" Title Translated English: "About ...
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Articles by Nathalie Balcar
Parmi les objets présents dans les collections d’art du XXe siècle, ceux réalisés en mousse de polyuréthane (PUR) ester posent de sévères problèmes de conservation liés principalement à la perte de leurs propriétés mécaniques due à leur dégradation par hydrolyse. Le but de ce travail a été de développer et tester un mélange de polymères de la famille des polysiloxanes qui permettrait de stabiliser les mousses PUR ester : un mélange à base d’AMDES (3-aminopropylmethyldiethoxysilane), hydrophile, et d’OTMS (octyltriméthoxysilane), hydrophobe. L’application de ce mélange suivant différents modes se voulant transposables à de véritables objets a été testée sur des échantillons de mousse PUR ester par des restaurateurs du patrimoine.
Le polychlorure de vinyle plastifié est un polymère synthétique, largement utilisé depuis le milieu du XXe siècle et jusqu’à nos jours, pour la production d’œuvres d’art et d’objets.Son état de conservation est souvent médiocre en raison de la migration des plastifiants. L’étude de l’impact du nettoyage et du mode de conditionnement de PVC vieillis naturellement en environnement muséal sur leur évolution permet d’envisager des conditions de conservation préventives et curatives optimales afin d’en limiter les dégradations.
In 2011, the C2RMF Restoration Department acquired a portable infrared spectrometer, which is used to identify plastics. It is therefore now possible to offer museums an in-situ, non-invasive analysis of their artefacts within the context of preventive conservation or as a preliminary study to restoration. Several analytical projects on different types of objects have enabled us to measure the potential and limits of this method of analysis."
du C2RMF, d’un ensemble de meubles du musée du Louvre
décorés de marqueterie Boulle a été l’occasion de s’intéresser aux
pigments utilisés pour mettre en couleur les parties en corne et en
écaille de tortue. Cette étude conduite exclusivement à partir de
micro-prélèvements a confirmé la technicité complexe de la mise en
oeuvre de ces couleurs.
Undertaken in the C2RMF workshops, the recent
restoration of pieces of furniture decorated with Boulle marquetry
from the Louvre, provided an occasion to examine the pigments
used to add colour to the parts made of horn and turtle shell. This
study, based on micro-samples alone, confirmed the complex
techniques involved in the application of these colours.
la gomme-laque par une autre couche de finition a débuté en 2002
au C2RMF. Elle avait pour but de mettre en évidence les éventuelles
relations entre dégradation et composition du vernis, d’évaluer le
rôle de protection sur les bois de vernis de compositions différentes
et enfin d’étudier l’influence de la lumière sur l’évolution dans le
temps des bois ainsi vernis. L’expérimentation mise en oeuvre s’est
focalisée sur un vernis décrit dans L’Art du menuisier-ébéniste
publié par André-Jacob Roubo en 1774. Plusieurs tests de mesure
d’épaisseur, d’apparence et de propriété mécanique ont été réalisés
sur des éprouvettes de bois de placage recouverts du vernis
sélectionné. Les résultats encourageants de son effet protecteur à la
photo-oxydation et à l’oxygène de l’air ont permis de mettre en place
un protocole en vue de son application comme protection de surface
pour le mobilier en marqueterie de métal du musée du Louvre.
Reflection on replacing traditional shellac varnishes
with another finish began in 2002 at the C2RMF. The aim was to
highlight the possible relationship between deterioration and the
composition of the varnish, to assess the role played by protective
coatings made of different ingredients on wood and, lastly, to study
the long-term effects of light on woods thus varnished. The
experiments conducted focused on a varnish described in L’Art du
menuisier-ébéniste, published by André-Jacob Roubo in 1774.
Several tests to measure thickness, appearance and mechanical
properties were carried out on samples of veneer coated in the
selected varnish. The encouraging results of its resistance to photooxidation
and the oxygen in the air enabled us to establish a
protocol for applying it to protect the surface of the metal marquetry
furniture now in the Louvre.
l’opportunité de s’intéresser à la colle qui assure le maintien des
différents éléments sur la structure en bois. Une nouvelle technique
d’investigation des colles, jusque-là absente des laboratoires
français dédiés à l’étude du patrimoine, a été évaluée et validée
pour connaître l’origine animale de ce matériau
The restoration of a piece of furniture offers researchers
a chance to study the glue used to hold the different parts of the
wooden structure together. A new investigative method of
determining the adhesive used, previously unavailable in French
laboratories reserved for cultural heritage studies, was tested and
validated. It confirmed the animal origin of this glue.
As part of the renovation programme for the 18th-century rooms of the Department of Decorative Arts, the Louvre asked the C2RMF to restore the carved wood decoration from the mansion called Le Bas de Montargis, built by Jules Hardouin-Mansart circa 1705. The restoration, which required over a year’s work, involved both the structure and the surface of the gilded decorative woodwork: the panelling was restored and the gilding underwent a complex process of removal, cleaning and harmonization. The scale of the preliminary study and restoration reflects a meticulousness that shows the changes in attitude towards decorative arts and large decorative schemes""
In the 17th century, Le Mans and the entire Maine region became an important production area for terracotta sculpture. While stone and wood were predominant in France at this time, sculptors in Le Mans were distinguished by their use of a technique possibly related to the arrival of Italian artists. The examination of the polychromy on twelve sculptures enabled us to detect the use of techniques unlike those usually practised in this period, namely a primer based on a local material, dolomite rock, and the presence of a white lead-based undercoat under this primer and the sgraffito decoration. A wide range of blues were also brought to light. One of these pigments stood out in particular. It was a copper blue, a synthetic azurite, whose pigment granules, when magnified, have a very distinctive appearance. The use of such a pigment can very probably be related to the industrialization and sale in England of verditer blue. This study thus provided initial insight into the work of artists who seemed to have innovated as opposed to using traditional techniques.""""
Mots-clés. Vase grec, étude scientifique, restauration illusionniste, Naples, Paris, XVIII e siècle, XIX e siècle, vernis, pigments, gomme laque, Brocchi.
Within the framework of an interdisciplinary research programme on the restoration history of Greek vases, a scientific investigation of about sixty objects from French museums was carried out at the C2RMF. After presenting the methods of examination and analysis used, the article describes the pictorial techniques employed by craftsmen specializing in the illusionist restoration of vases, for which Naples was the undisputed capital, in the late 18th and early 19th centuries. Lastly it highlights certain stylistic characteristics of the restorer Luigi Brocchi, as can be seen on the Louvre’s two Apulian kraters, K 66 and K 67
Keywords : Greek vase, scientific investigation, illusionist restoration, Naples, Paris, 18th century, 19th century, varnish, pigments, shellac, Brocchi
Parmi les objets présents dans les collections d’art du XXe siècle, ceux réalisés en mousse de polyuréthane (PUR) ester posent de sévères problèmes de conservation liés principalement à la perte de leurs propriétés mécaniques due à leur dégradation par hydrolyse. Le but de ce travail a été de développer et tester un mélange de polymères de la famille des polysiloxanes qui permettrait de stabiliser les mousses PUR ester : un mélange à base d’AMDES (3-aminopropylmethyldiethoxysilane), hydrophile, et d’OTMS (octyltriméthoxysilane), hydrophobe. L’application de ce mélange suivant différents modes se voulant transposables à de véritables objets a été testée sur des échantillons de mousse PUR ester par des restaurateurs du patrimoine.
Le polychlorure de vinyle plastifié est un polymère synthétique, largement utilisé depuis le milieu du XXe siècle et jusqu’à nos jours, pour la production d’œuvres d’art et d’objets.Son état de conservation est souvent médiocre en raison de la migration des plastifiants. L’étude de l’impact du nettoyage et du mode de conditionnement de PVC vieillis naturellement en environnement muséal sur leur évolution permet d’envisager des conditions de conservation préventives et curatives optimales afin d’en limiter les dégradations.
In 2011, the C2RMF Restoration Department acquired a portable infrared spectrometer, which is used to identify plastics. It is therefore now possible to offer museums an in-situ, non-invasive analysis of their artefacts within the context of preventive conservation or as a preliminary study to restoration. Several analytical projects on different types of objects have enabled us to measure the potential and limits of this method of analysis."
du C2RMF, d’un ensemble de meubles du musée du Louvre
décorés de marqueterie Boulle a été l’occasion de s’intéresser aux
pigments utilisés pour mettre en couleur les parties en corne et en
écaille de tortue. Cette étude conduite exclusivement à partir de
micro-prélèvements a confirmé la technicité complexe de la mise en
oeuvre de ces couleurs.
Undertaken in the C2RMF workshops, the recent
restoration of pieces of furniture decorated with Boulle marquetry
from the Louvre, provided an occasion to examine the pigments
used to add colour to the parts made of horn and turtle shell. This
study, based on micro-samples alone, confirmed the complex
techniques involved in the application of these colours.
la gomme-laque par une autre couche de finition a débuté en 2002
au C2RMF. Elle avait pour but de mettre en évidence les éventuelles
relations entre dégradation et composition du vernis, d’évaluer le
rôle de protection sur les bois de vernis de compositions différentes
et enfin d’étudier l’influence de la lumière sur l’évolution dans le
temps des bois ainsi vernis. L’expérimentation mise en oeuvre s’est
focalisée sur un vernis décrit dans L’Art du menuisier-ébéniste
publié par André-Jacob Roubo en 1774. Plusieurs tests de mesure
d’épaisseur, d’apparence et de propriété mécanique ont été réalisés
sur des éprouvettes de bois de placage recouverts du vernis
sélectionné. Les résultats encourageants de son effet protecteur à la
photo-oxydation et à l’oxygène de l’air ont permis de mettre en place
un protocole en vue de son application comme protection de surface
pour le mobilier en marqueterie de métal du musée du Louvre.
Reflection on replacing traditional shellac varnishes
with another finish began in 2002 at the C2RMF. The aim was to
highlight the possible relationship between deterioration and the
composition of the varnish, to assess the role played by protective
coatings made of different ingredients on wood and, lastly, to study
the long-term effects of light on woods thus varnished. The
experiments conducted focused on a varnish described in L’Art du
menuisier-ébéniste, published by André-Jacob Roubo in 1774.
Several tests to measure thickness, appearance and mechanical
properties were carried out on samples of veneer coated in the
selected varnish. The encouraging results of its resistance to photooxidation
and the oxygen in the air enabled us to establish a
protocol for applying it to protect the surface of the metal marquetry
furniture now in the Louvre.
l’opportunité de s’intéresser à la colle qui assure le maintien des
différents éléments sur la structure en bois. Une nouvelle technique
d’investigation des colles, jusque-là absente des laboratoires
français dédiés à l’étude du patrimoine, a été évaluée et validée
pour connaître l’origine animale de ce matériau
The restoration of a piece of furniture offers researchers
a chance to study the glue used to hold the different parts of the
wooden structure together. A new investigative method of
determining the adhesive used, previously unavailable in French
laboratories reserved for cultural heritage studies, was tested and
validated. It confirmed the animal origin of this glue.
As part of the renovation programme for the 18th-century rooms of the Department of Decorative Arts, the Louvre asked the C2RMF to restore the carved wood decoration from the mansion called Le Bas de Montargis, built by Jules Hardouin-Mansart circa 1705. The restoration, which required over a year’s work, involved both the structure and the surface of the gilded decorative woodwork: the panelling was restored and the gilding underwent a complex process of removal, cleaning and harmonization. The scale of the preliminary study and restoration reflects a meticulousness that shows the changes in attitude towards decorative arts and large decorative schemes""
In the 17th century, Le Mans and the entire Maine region became an important production area for terracotta sculpture. While stone and wood were predominant in France at this time, sculptors in Le Mans were distinguished by their use of a technique possibly related to the arrival of Italian artists. The examination of the polychromy on twelve sculptures enabled us to detect the use of techniques unlike those usually practised in this period, namely a primer based on a local material, dolomite rock, and the presence of a white lead-based undercoat under this primer and the sgraffito decoration. A wide range of blues were also brought to light. One of these pigments stood out in particular. It was a copper blue, a synthetic azurite, whose pigment granules, when magnified, have a very distinctive appearance. The use of such a pigment can very probably be related to the industrialization and sale in England of verditer blue. This study thus provided initial insight into the work of artists who seemed to have innovated as opposed to using traditional techniques.""""
Mots-clés. Vase grec, étude scientifique, restauration illusionniste, Naples, Paris, XVIII e siècle, XIX e siècle, vernis, pigments, gomme laque, Brocchi.
Within the framework of an interdisciplinary research programme on the restoration history of Greek vases, a scientific investigation of about sixty objects from French museums was carried out at the C2RMF. After presenting the methods of examination and analysis used, the article describes the pictorial techniques employed by craftsmen specializing in the illusionist restoration of vases, for which Naples was the undisputed capital, in the late 18th and early 19th centuries. Lastly it highlights certain stylistic characteristics of the restorer Luigi Brocchi, as can be seen on the Louvre’s two Apulian kraters, K 66 and K 67
Keywords : Greek vase, scientific investigation, illusionist restoration, Naples, Paris, 18th century, 19th century, varnish, pigments, shellac, Brocchi
A travers des études de cas, cette présentation fera le point sur la présence du matériau dans les collections, les dégradations observées et les questions en terme de conservation-restauration que cela implique. La question de l’analyse du PVC sera abordée pour mieux comprendre ce qu’il est possible de faire pour simplement confirmer la présence de ce matériau dans les objets et quelles sont les limites pour déterminer les différentes formulations. Une attention particulière sera portée à l’identification des plastifiants. Les processus de dégradations seront expliqués pour mieux comprendre l’évolution de ce matériau et démontrer qu’ils sont à l’origine de certains projets de recherche qui seront présentés dans d’autres communications de cette journée.
PVC can be very rigid, as in the case of sewer pipes, but it is in its flexible form that it is most widely used. Many of our everyday objects are made entirely or partly of PVC, and the material is therefore present in a wide range of heritage collections: design, toys, fashion, etc. Some artists have incorporated these objects into their creations, or chosen PVC because it was the material of choice. Some artists have incorporated these objects into their creations, or have chosen PVC because it was the only material to provide the properties required for their project. While this flexibility has made the material a commercial success, in terms of long-term conservation, it poses a number of problems, with objects showing various signs of deterioration: seepage, yellowing, deformation and cracking. At the root of all this deterioration lies the formulation of PVC, and more specifically its major additive, the plasticizer, which gradually leaves the material. Through case studies, this presentation will review the presence of this material in collections, the degradation observed and the conservation-restoration issues involved. The question of PVC analysis will be addressed to better understand what can be done to simply confirm the presence of this material in objects, and what the limits are for determining the different formulations. Particular attention will be paid to the identification of plasticizers. Degradation processes will be explained to better understand the evolution of this material and demonstrate that they are at the origin of certain research projects which will be presented in other papers of this day.
https://www.youtube.com/watch?v=AujTh02MJIw
Les acétates et les nitrates de celluloses font partie des premières matières plastiques. Ils ont été utilisés pour des applications très diversifiées et de ce fait sont présents dans de nombreuses collections. Leur identification par la simple observation s'avère souvent plus difficile que pour d'autres plastiques, notamment parce qu’ils ont été employés pour imiter des matériaux naturels. Elle est pourtant indispensable car ces matériaux émettent lors de leur dégradation des produits agressifs et il est nécessaire de prendre les mesures adaptées pour ralentir leur auto-dégradation et pour les isoler des objets voisins sensibles aux acides. De nombreuses techniques d‘analyse sont disponibles pour identifier les matières plastiques mais le caractère unique d’une œuvre ou à l’inverse la multitude d’objets conservés dans certaines collections font que deux techniques s’imposent pour répondre aux diverses questions émanant des musées. Au travers de cas d’étude, il sera possible d’apprécier l’apport d’un équipement permettant d’effectuer des analyses non destructives et, dans certains cas directement dans le musée grâce à sa configuration qui le rend portable, mais aussi de montrer ses limites qui obligent à avoir recourt à un microprélèvement de matière pour une étude en laboratoire
These contacts are often fruitless for different reasons: the manufacturers fail to respond to the information request, the product and its data sheet are no longer available, the documentation contains too vague information or the mentioned trademark corresponds to a variety of products.
The analyses of micro-samples from artworks are the only solution to have access to the chemical composition of the materials. For the characterization of the paint binder, the Py-GCMS is the most powerful analytical technique, especially when the sample is unique: no preparation is required and with the same pyrolysis temperature and chromatography parameters, as a screening method, it’s possible to identify many kind of paints: oils, alkyds, vinyls, acrylics, epoxy, urethane etc , some organic pigments and to detect additives in most cases present in trace quantities.
The results improve the knowledge of artist’s practices but more significantly could inform us on the state of preservation of the artwork and they are important tools for the conservation treatments. The following case studies demonstrate sometimes the necessity of analyses to modulate what it can be read, hear or see.
In this way, a photography showing Keith Haring preparing the paint for the mural at the Hopital Necker in Paris indicates the use of a paint named Pantex 1300®, a product for interior and exterior decoration. This paint is no longer produced in France and it’s possible to read on the can "acrylic". The analyses, from mural samples and from old Pantex 1300 cans, allow today to establish that it was a vinyl paint made with a PVAc copolymerised with a vinyl ester of fatty acid.
For the conservation of the painting le bain turc (1973) by Phlippe Artias [1], his wife has been interviewed. She explained that her husband begun to use vinyl paint in the 1970’s and acrylic at the ends of this decade. She specified that he used Caparol®, a vinyl dispersion for decorative purposes. Analyses confirmed the presence of this vinyl paints but revealed that some colours are made with an acrylic paint: it seems that Artias experimented acrylic sooner. The copolymer identified, a styrene-acrylic, suggests that it refers also to a decorative paint.
In the same manner, the son of Jurg Kreienbuhl explained that his father made his paints by mixing pigments to a product called Elotex 55 TW 25®. The technical data sheet detailed that it’s a homopolymer dispersion with two external plasticizers : dibutyle phtalate and tri-o-cresyl phosphate. The results obtained from samples of the painting Secteur d’Argenteuil(1965) [2], confirm the use of Elotex 55 TW 25® as binder for coloured layers but also for the varnish. They indicate that fifty years later both plasticizers are still presents in the binder, so the paint is still flexible.
Thank to the analyses of micro-samples of various colors from Le Grand serpent (1976) de Bernard Bazille,[3], a concomitant use of acrylic and vinyl paints also has been demonstrated while the artist mentioned to the curator only the use of Flashe paints. For the yellow color, in the same analyse, the PVAc binder and the azo pigment (PY3) could be identified. By comparison with our older (1980’s) Flashe paints references conserved at the C2RMF[4] it’s possible to specify that the hue of the yellow sampled is probably Lemon Yellow and not Senegal ( PY1+PY3) or Gold (PY1) yellow.
In all these examples, it is evident that collect reference materials allows us to have more accurate information that the ones available on archives (labels on tubes, catalogs or color chart). As a result, a series of paint samples (artist grade, household and industrial paints) from 1985 to nowadays is evolvingat the C2RMF (around 500 references) available in various amount from small samples (microscope slide) to original cans or tubes.
Acknowledgements
I would to thank Hélène Bluzat, Céline de Courlon, Emilie Faust and Will Shank for sharing the information they could collected through interviews of artists or their families, or by contacting artist foundation. The gathered information was valuable help in the interpretation of the analytical results and the knowledge development about these materials.
References
[1] Faust, E., Entre modernité et tradition : étude et conservation-restauration de Secteur d’Argenteuil, peint par Jürg Kreienbühl en 1965 (Fonds régional d’art contemporain d’Ile-de-France). Étude des dégradations d’une dispersion vinylique à plastification externe sur panneau dur et comparaison de différentes méthodes de nettoyage aqueux, Institut National du Patrimoine, Paris, 2015, unpublished.
[2] de Courlon, C. Le bain turc n°1” de Philippe Artias, 1973 (CNAP, Puteaux) : conservation-restauration d’une peinture vinylique sur toile de lin. Etude du phénomène de lustrage d’une peinture mate non vernie et comparaison de différents types de retouche. Institut National du Patrimoine, Paris, 2012, unpublished.
[3] Bluzat, H, C. Conservation-restauration d’une installation composite d’art contemporain : "Le grand serpent" de Bernard Bazile. Etude des matériaux constitutifs : matières plastiques, textile peint, lichen, crin de cheval. Institut National du Patrimoine, Paris, 2004, unpublished.
[4] Sonoda,N. & Rioux, J-P, Identification des matériaux synthétiques dans les peintures modernes I. Vernis et liants polymères. Studies in Conservation 35 (4), 1990,pp189–204
Réunies jadis par Henri Langlois, la collecte de ces œuvres se poursuit encore aujourd’hui. Mais au vue des problématiques de conservation présentées par certains de ces dessins réalisés à la gouache sur un support celluloïd, le catalogage menant à leur numérisation a dû être arrêté dans l’attente d’une solution de conservation satisfaisante.
L’intervention portera sur la nature de la collection des dessins d’animation, l'identification des matériaux, les problématiques de conservation rencontrées, les préconisations proposées, les solutions choisies ; ainsi que les perspectives offertes par la recherche au travers d’une étude sur les esters de cellulose.
The Cinémathèque française has a fine collection of animation drawings by such prestigious artists as Lotte Reiniger, Paul Grimault and even, very rarely, René Clément.
Once collected by Henri Langlois, the collection continues to this day. However, due to the conservation problems posed by some of these gouache drawings on celluloid, the cataloguing process leading to their digitization had to be halted until a satisfactory conservation solution could be found.
The talk will focus on the nature of the collection of animation drawings, the identification of their materials, the conservation problems encountered, the recommendations made and the solutions chosen, as well as the prospects offered by research into cellulose esters.
It is documented that in 1901 Mr. Lefranc ordered the construction of a new building in the factory of Issy-les-Moulineaux. This appendix would be dedicated to the production of Le Ripolin, an existing famous non-artistic oil based paint invented by Carl Julius Ferdinand Riep at the Briegleb Company in Holland in 1888.
Because of the fact that artistic and non-artistic oil paint brands (Lefranc and Ripolin) were localized and produced by the same company, and bearing in mind that the functionality of both paints is different, the goal of this research is to study Lefranc artist’s paint tubes colours, from the beginning of the 20th century, with the aim to find a discriminative criteria to differentiate artistic from non-artistic paints. This research was performed by characterizing the pigments, bindings, additives, and mixtures used in artists paint materials and establishing a comparison based on results published by the Art Institute of Chicago on pigments used on ready-mixed house paints (1).
A selection of forty Lefranc artist’s colours from 1930-1935 painted on canvas and located at the C2RMF has been studied. A multi-step analytical procedure has been applied on the Lefranc colours pigments, binders, and other additives on the composition of this brand of artist´s tubes. Analysis have been done by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM-EDX), to mainly identify the pigments and inorganic materials, and Pyrolysis Gas Chromatography (PyGC/MS) and GC/MS for the organic compounds.
Results obtained on the characterization of Lefranc artist paint has allowed to better understand the behaviour of the materials and it will help to determine conservation processes.