Caracterização material da policromia de um instrumento musical

A seguinte tese de mestrado foi hoje disponibilizada na internet:

Raquel Ludovina Menezes Estrompa, Cravo de Pascal Taskin (1782): Caracterização Material da Policromia Exterior, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2012.

Está aqui, com acesso livre.

Resumo:

Com o surgimento do piano a par de uma alteração dos gostos musicais da época, após o século XVIII o cravo caiu em desuso. Apenas oito cravos atribuídos a Pascal Taskin (1723-1793)sobreviveram até aos nossos dias, sendo o que pertence ao Museu da Música de Lisboa alvo de grande especulação. Embora este instrumento se encontre catalogado como um grand ravalement de um prestigiado cravo flamengo de Andreas Ruckers, foi apontado como falso Ruckers por Grant O’Brien. Devido à sua história e importância, desde 2006 este instrumento encontra-se classificado como tesouro nacional. Este estudo pretende compreender a autenticidade do ravalement através da caracterização material da policromia exterior do cravo, recorrendo a análises não destrutivas, não invasivas e in situ como reflectografia de infravermelho e espectrometria de fluorescência de raios X dispersiva de energias; e análises micro-destrutivas como microscopia óptica, microscopia electrónica de varrimento com espectrometria de raios X por energias dispersivas, micro-difracção de raios X, micro-espectroscopia de infravermelho com transformada de Fourier, pirólise seguida de cromatografia gasosa acoplada à espectrometria de massa e identificação de madeiras. Através do desenvolvimento de uma metodologia de trabalho adaptada, pode afirmar-se que o cravo em estudo tem pelo menos cinco intervenções. Estas intervenções não se encontram sistematicamente em todos os motivos, pelo que se podem entender como refrescamentos de alguns motivos decorativos de acordo com os gostos da época (diferentes figuras podem ter diferentes números de policromias e policromias de diferentes períodos de tempo). No que diz respeito à autenticidade do ravalement, pode concluir-se que embora se trate de um falso Ruckers, estamos perante um cravo sujeito a um autêntico ravalement.

Publicações sobre conservação e comportamento mecânico de pinturas de cavalete

Alain Roche, o autor de um importante livro sobre o comportamento mecânico das pinturas sobre tela (Comportement Mécanique des Peintures sur Toile. Dégradation et Prévention, Paris, CNRS Editions, 2003), disponibiliza na internet diversos artigos e comunicações de sua autoria que incidem sobre conservação e especialmente comportamento mecânico das pinturas de cavalete

Essas publicações estão aqui, com acesso livre.

(Devido a um problema de codificação dos endereços, alguns pdfs parecem ser inexistentes. O problema resolve-se substituindo nesses endereços “%C3%A9” por “%E9”.)

As publicações são as seguintes:

• Alain Roche, "A propos de la restauration de l'art moderne et contemporain", Conservation-Restauration, 2, 1985, pp. 18-19.

• Alain Roche, "Proposition d'une méthode de doublage à froid", Conservation-Restauration, 5-6, 1986, pp. 12-15.

• Alain Roche, "Notes sur les origines du vieillissement prématuré des peintures contemporaines", Conservation-Restauration, 7-8, 1987, pp. 22-24.

• Sophie Lennuyeux-Comnène, Alain Roche, "Le doublage des dessins de grand format sur non-tissé polyester étudié en fonction d'une série d'adhésifs", in J. Bridgland (ed.), ICOM Committee for Conservation 12th Triennial Meeting, Lyon, London, James & James, 1987, pp. 517-524.

• Alain Roche, "Mécanismes de formation d'un film d'émulsion", Conservation-Restauration, 9, 1988, pp. 34-36.

• Alain Roche, "Comportement de l'adhésif dans un doublage", Conservation-Restauration, 11, 1989, pp. 18-20.

• Alain Roche, "Etude comparative des toiles de lin et de polyester dans les doublages de tableaux", in Actes du 2e colloque de l'ARAAFU, Paris, ARAAFU, 1989, pp. 149-156.

• Alain Roche, "Les matériaux composites polychromes dans les commandes publiques d'oeuvres d'art: étude de cas Couple d'amoureux aux yeux de fleur d'amandier de Miro", in J. Bridgland (ed.), ICOM Committee for Conservation 12th Triennial Meeting, Lyon, London, James & James, 1989, pp. 876-880.

• Alain Roche, "Dispositif de montage des toiles peintes, interventions préventives", in Actes du 3e Colloque International de l'ARAAFU, Paris, ARAAFU, 1992, pp. 273-278.

• Alain Roche, J. F. Hulot, "Dispositif de montage des toiles peintes, interventions préventives", Science et Technologie de la Conservation et de la Restauration des Oeuvres d'Art et du Patrimoine, 3, 1993, pp. 74-77.

• Roche, "Influence du type de chassis sur le vieillissement mécanique d'une peinture sur toile", Studies in Conservation, 38(1), 1993, pp. 17-24.

• Alain Roche, C. Bergeaud, J. F. Hulot, "Altérations liées aux interventions sur les supports toile: Leurs effets, leur réversibilité", in Actes du 4e Colloque International de l'ARAAFU, Paris, ARAAFU, 1995, pp. 109-116.

• Alain Roche, "Rentoilage traditionnel-désentoilage: Analyse des tensions", in Actes du 4e Colloque International de l'ARAAFU, Paris, ARAAFU, 1995, pp. 103-108.

• Alain Roche, "Etude du comportement mécanique des dessins de grands formats doublés sur des matériaux non-tissés", in J. Bridgland (ed.), ICOM Committee for Conservation 11th Triennial Meeting, Edinburgh, Scotland, London, James & James, 1996, pp. 545-551.

• Alain Roche, "Pressure-sensitive adhesives for the attachment of reinforcing canvases to the back of paintings", Studies in Conservation, 41(1), 1996, pp. 45-54.

• Alain Roche, "Comportement mécanique des peintures à la colle et à l'huile sur papier", Technè, 13-14, 2001, pp. 56-62.

• Roche, L. Dessennes, "The consolidation of flaking gouache on Japanese paper", Restaurator, 23(4), 2002, pp. 240-255.

• Alain Roche, "Approche du principe de réversibilité des doublages des peintures sur toile", Studies in Conservation, 48(2), 2003, pp. 83-94.

• Alain Roche, "Comportamento meccanico dei dipinti su tela: Valutazione della stabilità meccanica alle variazioni di umidità e temperatura", in Minimo Intervento Conservativo Nel Restauro Dei Dipinti, Verona, CESMAR7, 2004, pp. 61-72.

• Alain Roche, D. Fromageot, N. Pichon, J. Lemaire, "Durabilité des peintures polyuréthannes utilisées pour la rénovation des sculptures de Miro, installées à la défense", in J.-C. Bernier, F. Guinot, J.-P. Mohen, P. Potier (ed.), Art et Chimie. Les Polymères, Paris, CNRS, 2004, pp. 41-44.

• Alain Roche, "Contribution de la Conservation Restauration dans l'authentification des oeuvres sur toile", Petites Affiches, 149, 2005, pp. 14-15.

• Alain Roche, "Comportement mécanique des peintures sur toile: Evaluation de la stabilité mécanique aux variations d’humidité et de température", in 1er Seminario Internacional de Conservación de Pintura. El Soporte Textil: Comportamiento, Deterioro y Criterios de Intervención, Valencia, Editorial Universidad Politécnica de Valencia, 2005, pp. 189-212.

• Alain Roche, "Per una nuova lettura del concetto di adesione e decoesione: aspetti fisico-chimici e meccanici", in L'attenzione Alle Superfici Pittoriche. Materiali e Metodi Per il Consolidamento e Metodi Scientifici Per Valutarne l'Efficacia. Atti del Congresso, Verona, CESMAR7, 2006, pp. 61-72.

• Alain Roche, Stéphanie Doucet, "Propriétés mécaniques des peintures à la cire et à l'encaustique", Technè, 23, 2006, pp. 20-24.

• Alain Roche, Jean-Pierre Chambard, "Détection par thermographie et TV-holographie des défauts de la voûte de la Galerie des Glaces du château de Versailles", Technè, 25, 2007, pp. 32-34.

• Alain Roche, S. Ottolini, D. Riggiardi, "Studio meccanico del potere consolidante di alcuni adesivi in rapporto a cariche e pigmenti utilzzati in pittura", in D. Kunzelman (ed.), L'attenzione Alle Superfici Pittoriche. Materiali e Metodi Per il Consolidamento e Metodi Scientifici Per Valutarne l'Efficacia - 2. Atti del Congresso, Verona, CESMAR7, 2008, pp. 137-158.

• Alain Roche, "Rôle du châssis à tension auto-régulée", in Art d’aujourd’hui - Patrimoine de demain. Conservation et restauration des oeuvres contemporaines, Paris, SFIIC, 2009, p. 200.

• Alain Roche, Véronique Sorano-Stedman, "Triptyque de Miro Bleux I, II, III - dérestauration, restauration-conservation", in S. Martín Rey, V. Guerola Blay (ed.), Congreso Internacional de Restauración de Pinturas sobre Lienzo de Gran Formato, Valencia, Universidad Politécnica de Valencia, 2010, pp. 309-328.

• Alain Roche, "Témoignage d'un restaurateur, ingénieur", Patrimoines - Revue de l'institut national du patrimoine, 6, 2010, pp. 94-97.

Sobre o princípio da intervenção mínima

A seguinte tese de mestrado está disponível online com acesso livre:

Ludovic Roudet, L'Intervention Minimale en Conservation-restauration des Biens Culturels: Exploration d'’une Notion, Paris, Université Paris I Panthéon-Sorbonne, 2007.

Está aqui.

Resumo:

La formulation de la notion d’intervention minimale est récente : son apparition tardive dans les codes de déontologie professionnelle ne remonte qu’aux années 1980. Mais au cours de la lente maturation de cette notion, de grands esprits européens — architectes, artistes, historiens ou scientifiques — et certains domaines de la conservation-restauration vont faire figure de guide, et ouvrir la voie à un autre mode de pensée : l’acceptation de certaines incomplétudes au nom de la sauvegarde d’autres valeurs portées par l’objet. Si la science joue un rôle croissant dans la compréhension de la structure des oeuvres, elle apporte également une désillusion majeure : le constat qu’à l’échelle de la matière, toute intervention provoque un bouleversement irréversible. Sauf à n’envisager que l’aspect matériel d’un bien culturel, l’intervention minimale ne peut adopter une position fixe ; divers exemples illustrent son déplacement en fonction de son ontologie : statut, usage, origine culturelle ou intention du créateur. Dès que l’on s’éloigne d’une conception classique et occidentale du bien culturel, notre déontologie se trouve déstabilisée : appliquée à une culture différente ou confrontée à l’art contemporain, elle ne fonctionne plus. La seule possibilité de conciliation semble résider dans le changement de statut.  L’intervention minimale est aujourd’hui fréquemment invoquée en conservation restauration des supports toile en peinture de chevalet. Différents cas exemplifient les variations possibles d’un minimum requis en fonction du contexte de chaque oeuvre.

Restauro e des-restauro em pintura mural

A seguinte tese de mestrado está disponível na internet com acesso livre:

Guylaine Ruard, Restauration/dérestauration en Peinture Murale: Un Problème Entre Histoire et Actualité, Grenoble, Université Pierre Mendès France, 2007.

Está aqui.

Resumo:

Ce mémoire dresse un bilan à jour de la question et des problématiques de la restauration/dérestauration dans le domaine de la peinture murale. Ces recherches s'inscrivent dans un projet personnel et professionnel, mais aussi scientifique. En effet, ce travail énonce les principes fondamentaux de la restauration, et les divergences qui peuvent exister entre la théorie et la pratique. Les deux premiers chapitres évoquent l'évolution technique et historique de la peinture murale, ainsi que la progression de la profession de restaurateur et de sa déontologie. Le dernier chapitre se consacre à l'étude d'exemples représentatifs de chantiers de restauration afin d'aborder les enjeux et facteurs décisifs qui justifient ou non une dérestauration.

Estudo de objectos de bronze e de bronze dourado

Outra tese de doutoramento que acabou de ser discutida e disponibilizada na internet é a seguinte:

Laura Brambilla, Multianalytical Approach for the Study of Bronze and Gilded Bronze Artefacts, Milano, Università degli studi di Milano, 2011.

Está aqui, igualmente com acesos livre.

Resumo:

This work focuses on one of the most common metal alloy used in the field of art: bronze. Bronze was discovered about 3500 years BC and was used in the antiquity to create tools, weapons, armour, and later coins, medals, sculptures and other works of art. Bronze objects were harder and more durable than stone or copper ones and easier to work than the iron ones. These characteristics contributed to render bronze a material largely widespread through millenniums. Of great interest are also the colourings that outdoor bronze exhibit. In fact, when exposed to atmosphere, copper and its alloys form a thin layer of corrosion products, called patina. The naturally formed patinas have different colours depending on the surrounding environment and its chemical composition: urban, rural, marine. A patina on a bronze artwork not only protects the metallic substrate, but also enhances the aesthetic of the artistic objects. Coloured patinas form spontaneously on copper alloys by very slow controlled corrosion either in the presence of moisture, carbon dioxide, and oxygen, or other chemical species present in the atmosphere. Patinas may also be created artificially by artists for aesthetic and protective reasons. Investigation of the corrosion behaviour of copper patinas is of utmost importance for understanding the atmospheric deterioration of bronze monuments as well as objects of cultural heritage. During this work, a multidisciplinary approach has been applied in order to thoroughly understand the degradation mechanisms of the patinas of corrosion products that naturally form over bronzes surface. Particular attention has been paid to the transformations connected to relative humidity variations. To further adorn and make more precious the artefacts, bronze statue were also gilded. The gilding of a bronze statue allows to obtain an object that has the same aspect of a statue made of pure gold, but that is less expensive and simultaneously presents certain resistance characteristics. Examples of gilded bronze artworks can be found in the Italian artistic patrimony, such as, for example, the horses of St. Mark in Venice, the statue of Marcus Aurelius in Rome and the Porta del Paradiso, the eastern portal of the Baptistery in Florence. The latter has been the starting point of this work. This important gilded bronze of the Italian Renaissance was damaged during the flood that devastated Florence in 1966 and since then a long process of restoration and characterization of the artwork started and it is still going on. The study of gilded bronze artworks is a difficult topic in the field of cultural heritage due to the complex structure (tri-layer) of the material. The structure, in fact, is composed by a metallic substrate (bronze), the gold and, between the two metals, a layer of corrosion products formed during time as a consequence of degradation processes. The presence of hygroscopic salts between the gilding and the bronze may lead to the detachment of the gold layer as a consequence of volume variation related to changes in the crystalline forms of the copper salts composing the patina. At the beginning of this work, the “Porta del Paradiso” was at the last stage of a long process of restoration carried out by the Opificio delle Pietre Dure and the door was almost ready to be finally unveiled to the public. At that stage of the research it was necessary to identify the best exposure option for this precious and unfortunately very unstable masterpiece of the Renaissance. The optimal display option for the “Porta del Paradiso” had to take into account two important factors: first, it was necessary to choose an environment that could assure the best preservation condition for the restored artwork and therefore able to block corrosion; second, a solution that could provide an enjoyable viewing experience for the public was also expected. To fulfil these requirements, three different showcases were tested: a) a closed showcase purged by nitrogen; b) a closed showcase with low and controlled relative humidity; c) an open showcase with controlled microclimate that should create the same local environmental conditions as the showcase with low RH, with the big advantage of avoiding a glass panel between the object and the visitor. To evaluate the resulting conditions of conservation imposed by the three different showcases, qualitative and quantitative studies were necessary. Unfortunately the techniques commonly used to obtain quantitative data regarding corrosion phenomenon from metallic artefacts (i.e. polarization resistance and electrochemical impedance spectroscopy) are not suitable for bimetallic artefacts such as the “Porta del Paradiso”. Initially some replicas of the “Porta del Paradiso”, with the same bronze alloy and the same gilding technique of the door, were produced by the OPD. It was then necessary to age these samples in order to obtain a system that reproduces the actual condition of the artwork. For this reason a new methodology was developed during this work for the electrochemical artificial ageing of gilded bronze specimens. Unfortunately, due to the unavoidable short circuit between gold and bronze, these aged samples were not suitable to obtain quantitative data concerning the corrosion rate of the door. An alternative solution appeared to be the realisation of galvanic sensors, used as replicas of corroded gilded bronzes, that were developed and used to measure the macrocouple current of the system “Bronze-Patina-Gold”, that is directly correlated to the corrosion rate by Faraday’s law. The most critical steps during the development of the galvanic sensors are: a) the preparation of an artificial patina of corrosion products and b) the gilding methodology. The realisation of an artificial patina proved to be a very crucial point, because the patina has to fulfil a series of important and specific requirements, such as: 1 – composition similar to the real cases, 2 – adequate thickness, 3 – good homogeneity, 4 – good adhesion to the substrate, 5 – adequate electrical resistance. The main constituents of natural patinas have been identified after a thorough literature review. Then a procedure for the realisation of artificial patinas with similar composition was developed. Different kind of patination techniques available in literature (such as chemical and electrochemical patination) have been tested to obtain the artificial layer of corrosion products. Unfortunately none of them allowed to obtain a patina with all the required characteristics. A new methodology was then developed for the patina used to realise the galvanic sensors. This method is inspired by the so-called “applied paste” and consists in spreading on the metallic surface a specific mixture of copper salts and water .This procedure allows to control precisely all the parameters previously mentioned. Concerning the second critical step, i.e. the gilding procedure, two different methodologies have been tested: sputtering and gold leaf application. The best one revealed to be the application of a gold leaf. A first set of galvanic sensors was realised and used for the solution of the “Porta del Paradiso” case. In that occasion they proved to be a very powerful tool and allowed the identification of the best display option for the doors. However these sensors presented some evident problems of durability and reproducibility. The methodology of preparations of the galvanic sensors has subsequently been completely revised and improved leading to the obtainment of new galvanic sensors, named “gold leaf galvanic sensors”, that proved to be much more durable and reproducible. The galvanic sensors can be used both for monitoring the corrosion rate of real objects and for testing new conservation or cleaning procedures.

Identificação de corantes com interesse em arte e arqueologia

Acabou de ser disponibilizada online a seguinte tese de doutoramento que foi discutida há poucos dias:

Federica Pozzi, Development of Innovative Analytical Procedures for the Identification of Organic Colorants of Interest in Art and Archaeology, Milano, Università degli studi di Milano, 2011.

Está aqui, com acesso livre.

Resumo:

Organic colorants obtained from natural sources such as plants and insects have been widely used as textile dyes or lake pigments for paintings, sculptures and other kinds of polychrome works of art since ancient times until the second half of the 19th century, when the industrial production of synthetic dyes had begun. Chemical investigation of such materials is of great interest to art historians, restorers and art conservators. In fact, the analysis of ancient dyes can be of help in revealing what kind of substances were available in particular periods and geographical areas, providing valuable data about the historical context of a work of art, the lifestyle and the technical knowledge reached by a certain population in a given historical age, shedding light on the possible interactions between different cultures as well as the trade routes and commercial transactions which may have allowed the usage of a particular colorant far from its geographical source. Moreover, discovering nature and origin of the coloring substances employed in the production of a work of art can provide precious information regarding its original color and appearance, thus offering new insights into the artist’s choices and original intention, the techniques used and the dates ante quem and post quem the art object was produced, possibly leading to the uncovering of falsifications and forgeries. Furthermore, scientific analysis applied to the study of art materials and, specifically, of pigments and dyes, may contribute to assess suitable conservation and restoration procedures to be applied to paint defects and degraded pigments in works of art of any kind; in fact, time, environmental conditions and several other circumstances unavoidably cause damage and deterioration to art objects and artifacts, which therefore require careful conservation to be safeguarded as important elements of our cultural heritage. The identification of historical dyes is currently one of the most challenging tasks in the chemical investigation of art materials, for three main reasons. First of all, colorants in works of art and archaeological textiles are usually included in complex matrixes such as paint layers or cloth fibers, where they are present in mixture with other substances, such as binding media or mordants, and in very low concentrations due to their high tinting power. Besides, sampling of art objects is always limited to microscopic fragments, when at all allowed. An additional analytical challenge is posed by the remarkable susceptibility to deterioration of organic materials, which can undergo a number of chemical degradation processes leading to the formation of specimens with a different molecular structure in comparison to the primary organic dye. Several instrumental techniques, of both chromatographic and spectroscopic type, have been employed for the detection of colorants over the years. In recent times, the great potential of SERS has been appreciated, as the adsorption of the analyte on nanosized metal surfaces, resulting in a significant enhancement of the Raman scattering intensity and strong fluorescence quenching, leads to obtaining a specific fingerprint for many organic substances, markedly reducing the amount of sample that would be otherwise required for analysis. However, on the other hand, SERS poses a whole set of challenges, as only a small number of molecules have been studied so far and the necessity of searchable databases of reference materials is still to be fulfilled; moreover, SERS is not a separation technique, and therefore it often suffers from spectral interferences due to the presence of impurities or matrix components. In this context, the present doctoral thesis work aims to the improvement of pre-existing analytical methods as well as to the development of innovative procedures for the identification of organic dyes of artistic and archaeological interest, with special attention being devoted to SERS. The scientific results here reported are the fruit of a research activity carried out both at Università degli Studi di Milano and in the Department of Scientific Research of the Metropolitan Museum of Art (New York, USA). First of all, an effective experimental protocol for SERS analyses on silver colloids aggregated by NaClO4 was optimized and a wide spectral database of historical natural colorants was thus assembled, containing among the others the spectra of several dyes never studied before. The SERS procedure developed, in association with complementary analytical investigations of different kind, was then successfully applied to the identification of a yellow dye in ancient wool threads from the Libyan Sahara and to the detection of several colorants in Kaitag textiles, a unique embroidered textile art form from Caucasus. Work carried out at the Metropolitan Museum of Art comprises a comparative study of the most relevant SERS approaches recently introduced in art analysis: relative merits and drawbacks of HF hydrolysis and non-hydrolysis methodologies were evaluated, and a two-step procedure for the investigation of organic dyes in works of art was proposed. Results obtained from reference dyes were compared with those achieved on samples taken from a number of artworks and ancient objects, including masterpiece oil paintings, musical instruments, archaeological textiles and lake pigments. Watercolors from a historical Winsor & Newton handbook dating to 1887 were then characterized using SERS and ordinary Raman spectroscopies, and a database of original art materials was acquired, to be used for dating as well as in authentication and identification studies. Also, coupling of TLC and SERS was investigated and tested as a promising tool for the separation and identification of the main alkaloid constituents of Syrian rue dye. Finally, a comprehensive Raman study of monobromoindigo, component of the historical colorant Tyrian purple, was performed, together with a detailed assignment of the spectral lines observed by comparison with density functional theory (DFT) quantum mechanical calculations.

Studies in Conservation, vol. 56, n.º 4, 2011

Acabou de ser publicada pelo IIC a revista Studies in Conservation, vol. 56, n.º 4, de 2011.

Como é explicado no editorial do presente número, com o próximo inicia-se um novo formato e uma nova fase.

Índice:

• Sabine Zorn, Sebastian Dobrusskin, 'Diasec' and Other Finishing Techniques: Investigation of Accelerated Light Fading, pp. 257-266

• Andrea Venosa, Daniel Burge, Douglas Nishimura, Effect of Light on Modern Digital Prints: Photographs and Documents, pp. 267-280

• Véronique Vergès-Belmin, Alison Heritage, Ann Bourgès, Powdered Cellulose Poultices in Stone and Wall Painting Conservation: Myths and Realities, pp. 281-297

• Elena M. Perez-Monserrat, Maria J. Varas, Rafael Fort, Monica Alvarez de Buergo, Assessment of Different Methods for Cleaning the Limestone Façades of the Former Workers Hospital of Madrid, Spain, pp. 298-313

Investigação, conservação e restauro de materiais e objectos cartográficos

Acabou de ser livremente disponibilizado online o seguinte livro:

María Domingo, Iolanda Muíña (ed.), Investigación, Conservación y Restauración de Materiales y Objetos Cartográficos, Madrid, Ministerio de Educación, Cultura y Deporte, 2011.

Está aqui.

Índice:

• Jaime Alvar, La Tierra vista desde el mar: representaciones cartográficas y descripciones literarias, p. 8

• Domingo Plácido y Javier Sánchez-Palencia, La percepción diacrónica del espacio, p. 18

• Luisa Martín-Merás, Las cartas portulanas. Origen y desarrollo, p. 27

• Mónica Herrera Casais, Un mar para navegar, imaginar y compartir: la imagen del Mediterráneo y otras geografías en la carta náutica de Ibrahim al-Mursi, p. 42

• Carmen Líter Mayayo, Tesoros de la cartografía en la Biblioteca Nacional de España, p. 56

• Emma García Alonso, Una vuelta más a las tablillas de Astorga, p. 70

• Andrés Serrano, Los globos celestes y terrestres, p. 81

• Pedro García, La conservación de mapas y planos contemporáneos, p. 97

• José Manuel Lodeiro, El documento geométrico en el IPCE, p. 108

• María Asunción Martín, La Real Sociedad Geográfica y la cartografía, p. 119

• M. ª Josefa Jiménez Albarrán, Materiales y objetos cartográficos del Museo Nacional de Ciencia y Tecnología: una pequeña muestra, p. 128

Análise de Pigmentos por Técnicas de Espectroscopia e Difracção de Raios X

A seguinte tese de mestrado está disponível na internet com acesso livre:

Ana Carina Pereira Fernandes, Análise de Pigmentos por Técnicas de Espectroscopia e Difracção de Raios X, Coimbra, Faculdade de Ciências e Tecnologia da Universidade de Coimbra, 2011.

Está aqui.

Resumo:

Para o desenvolvimento das áreas de restauro e conservação tornou-se de extrema importância a análise das obras de arte com recurso a técnicas de análise diferentes e complementares. O estudo de pigmentos veio-se a revelar um instrumento de valor na caracterização de obras de arte, sendo uma mais-valia para a história da arte, uma vez que fornece informações relevantes sobre as obras. Neste trabalho, foram feitos estudos de pigmentos e de algumas amostras de obras de arte com recurso a técnicas de análise não destrutivas (Espectroscopia micro-Raman e Fluorescência de raios-X) e destrutivas (Difracção de raios-X) para se obterem resultados sólidos. O objectivo principal deste trabalho é a realização de uma base de dados para a aparelhagem de espectroscopia micro-Raman, de baixa resolução (cerca de 50 cm^-1), com base nos pigmentos comprados para mais tarde, ao analisar obras de arte, ser possível obter a sua composição.

Problemas de conservação de pintura mural causados pelo envelhecimento do poliacetato de vinilo

Acabou de ser disponibilizada online a seguinte tese de doutoramento:

Anna Nualart i Torroja, Les Pintures Murals Negres del Monestir de Pedralbes: Problemes de Conservació-restauració Causats Per l'Envelliment de l'Acetat de Polivinil, Barcelona, Universitat de Barcelona, 2006.

Está aqui, com acesso livre.

Resumo:

El mes de juny de l’any 2000 es va inaugurar l’exposició “Petras Albas. El monestir de Pedralbes i els Montcada (1326-1673)” al Museu-Monestir de Pedralbes. Aquesta exposició, que havia de ser temporal i es va acabar convertint en semi-permanent, estava constituïda en la seva major part per obres del fons de la collecció de les monges, amb l’aportació externa d’alguna altra obra per completar-ne el discurs museològic. Els comissaris de l’exposició havien inclòs entre les peces escollides les anomenades “pintures negres”, que són l’objecte principa d’aquesta tesi. Aquestes pintures murals són una de les obres menys vistoses, de les que tenen menys protagonisme, d’entre les que integren la collecció del Museu-Monestir de Pedralbes. No semblen, a priori, l’obra més interessant des del punt de vista d’un encàrrec professional per a un conservador-restaurador. però el poc que es coneix de les pintures negres i la seva raresa (es desconeixen altres pintures similars que s’hagin pogut conservar), així com les patologies derivades del seu arrencament i traspàs l’any 1974, aconsellaven aprofundir en el seu estudi, que, mica en mica, va acabar resultant absorbent. Volem posar en relleu amb el treball realitzat el fet que de l’estudi d’un objecte en procés de restauració, aparentment intranscendent i opac, que s’ha mantingut al marge de l’interès dels estudiosos, amb la voluntat de respondre les preguntes menys evidents, és possible arribar a entendre com pensaven i vivien les persones d’una època tan allunyada del nostre temps com és el segle XIV, més enllà d’intentar resoldre els problemes estrictes de conservació que pugui presentar. El treball es va iniciar l’any 2000 amb l’encàrrec de restaurar les pintures negres traspassades per poder-les exhibir en condicions acceptables en l’exposició. El primer contacte amb les pintures va ser una inspecció visual en què es va constatar un problema important de conservació-restauració i es va elaborar una llista de qüestions per respondre que abraçaven un espectre d’àmbits força diversos. La informació que hem anat obtenint de la investigació duta a terme s’ha organitzat en els quatre capítols de la tesi. Al primer capítol s’ha agrupat la informació referent a l’entorn de les pintures: qui les va encarregar i on eren quan es van realitzar. S’ha fet un treball de documentació de la figura de la reina Elisenda i de la seva obra, el monestir de Pedralbes, des de la fundació d’aquest fins la mort de la reina fundadora. Al segon capítol s’han posat en comú dos fonts de documentació fonamentals per conèixer com es va dur a terme l’arrencament i el traspàs de les pintures negres: una filmació en pellícula de 16 mm realitzada per documentar el procés i la fitxa del catàleg de l’exposició Barcelona restaura, realitzada l’any 1980. S’ha pogut recórrer també, sortosament, a informació de primera mà d’alguns dels protagonistes de la intervenció: el Sr. Joaquim Pradell i Ventura, restaurador de l’antic Servei de Museus d’Art, i la Sra. M. Assumpta Escudero i Ribot, primera directora del Museu- Monestir de Pedralbes i impulsora de les excavacions que van perpetre identificar part del palau de la reina Elisenda al mateix monestir, tots dos jubilats en l’actualitat. El tercer capítol aprofundeix en el tractament realitzat a les pintures negres en el moment del seu traspàs a un nou suport. En aquest moment, es consuma el canvi d’estat de les pintures, que deixen de ser «pintures murals» per passar a convertir-se de fet en un nou bé cultural moble. S’ha obtingut la informació del procés amb l’ajut de les fonts citades en el segon capítol, però l’estudi de les pintures s’ha complementat amb anàlisis físiques i químiques de la seva estructura i composició. S’ha dut a terme també un estudi de l’adhesiu utilitzat per al traspàs de les pintures al nou suport, el poliacetat de vinil, i del procés d’envelliment o degradació que aquest pateix, atès que és el principal causant de les patologies que presenten actualment les pintures negres El quart capítol vol respondre les preguntes menys pragmàtiques que generen les pintures negres, és a dir aquelles qüestions relacionades amb el seu significat. S’hi recull la informació de l’anàlisi iconogràfica de les pintures i també els referents culturals i religiosos del moment en què es van crear, així com una aproximació a la presència de la mort en la vida quotidiana al segle XIV. Per respondre aquestes qüestions ha calgut recórrer a la bibliografia especialitzada en iconografia i simbologia, i a les mateixes fonts de la literatura religiosa que les ha generades, així com a la bibliografia sobre la història de les mentalitats, el pensament i la vida quotidiana. Finalment, a l’apèndix documental s’aporten documents de referència necessaris per a la consulta durant la lectura de la tesi.

Estudo e conservação de uma pintura do Palácio Nacional da Pena

A seguinte tese de mestrado acabou de ser colocada na internet com acesso livre.

Dina da Costa Reis, The materials, technique, conservation treatment and after-care of interior de um convento, Lisboa, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2011.

Está aqui.

Resumo:

This thesis concerns the study of the materials and techniques of the painting on canvas “Interior de um Convento” belonging to the Portuguese monument Pena National Palace (PNP) and the description of the conservation treatment carried out. The study required the use of several examination and analysis tools such as OM (Optical Microscopy), UV (ultraviolet) and IR (infrared) photography, µ-EDXRF (Energy Dispersive X-ray Fluorescence), µ-Raman (Raman spectroscopy) µ-FTIR (Fourier Transform Infrared Spectroscopy) and SEM-EDX (Electron Scanning Microscopy with Energy Dispersive X-ray Spectroscopy). The conservation treatment focused on minimal intervention with the purpose of maintaining the integrity of a nineteen century painting that has never been restored until the present date. Simultaneously, a project to investigate the best back and front protection system for the PNP’s paintings collection was initiated. Relative Humidity (RH) and temperature fluctuations were measured in the Palace and inside the half-closed and fully closed systems used to protect twelve model paintings constructed for the purpose. The objective was to choose the best protection system for dampening RH and temperature fluctuations while preventing the risk of mould occurrence. The preliminary results (4 months of readings) showed that the risk of mould growth requires further study for in a more prolonged period which encompasses seasonal changes.