Papers by António João Cruz
Minerals, 2023
The paint materials and techniques of The Descent from Cross, a panel painting attributed to the ... more The paint materials and techniques of The Descent from Cross, a panel painting attributed to the Portuguese painter Francisco João (act. 1558–1595), were investigated with a combination of visible, ultraviolet, and infrared imaging and an analysis of paint samples with microscopic, spectroscopic, and chromatographic techniques. The colour palette is composed of lead white, lead–tin yellow, minium, vermilion, ochres of different colours, umber, smalt, azurite, verdigris, charcoal black, and a variety of different-coloured red lakes made of brazilwood and cochineal. An oil-based medium was identified. The characterisation of the pigment mixtures, paint build-up, and particular paint handling techniques enabled us to determine their role in the style and formal appearance of this painting and to discuss Portuguese painting practices in the larger context of 16th-century European painting. Mineral and elemental associations or impurities in the blue pigments, as well as degradation issues affecting minium, and smalt paints were reported. In particular, the deterioration of the glass matrix in some of the smalt particles mixed in lead white paint raises special concern.
Italian influence in a Portuguese Mannerist painting (part II): a matter of image or a matter of technique?
Studies in Conservation, 2023
The panel depicting The Descent from the Cross, painted in 1620 by the Portuguese artist Pedro Nu... more The panel depicting The Descent from the Cross, painted in 1620 by the Portuguese artist Pedro Nunes (1586-1637), shows a clear Italian formal influence. The painter's colour palette was identified in another paper. The panel is now investigated from a technical perspective, discussing aspects related to the support, preparatory system, and paint layer build-up. The research is based on the visual inspection of the painting's surface with complementary imaging techniques and on the analysis of the materials from the preparatory layers with microscopic and spectroscopic techniques. The characterisation of the painting technique revealed an ingenious use of colour that is based on the understanding of the optical and handling properties of oil paint. This knowledge is illustrated by the painter's ability to exploit and combine a range of different oil painting techniques, such as glazing, scumbling, wet-in-wet, or wet-in-dry painting; by his formulation of a wide variety of pigment mixtures; and by his use of diverse and often complex layering systems - some quite unconventional for Portuguese painting practice. The material and technical originality of this painting clearly reflects Nunes' international Roman experience and his desire to update the Portuguese mainstream practice of his time.
Annunciation or Adoration? The workshop practice and the hesitations of a Portuguese mannerist painter revealed by infrared reflectography
Archaeological and Anthropological Sciences
The examination with infrared reflectography of the Annunciation and the Adoration of the Shepher... more The examination with infrared reflectography of the Annunciation and the Adoration of the Shepherds, two panels from a dismembered altarpiece attributed to the mannerist painter Francisco João (doc. 1558–1595), revealed the first documented example in Portuguese painting of the overlapping of two underdrawing layouts, each with a different subject, in a single panel painting. The paintings were examined under visible radiation and infrared reflectography was used to investigate the underdrawing in terms of the materials, graphic layout and function. Results from a previous study on the ground layers and underdrawing materials of these paintings, obtained with the analysis of micro-samples with microscopic and spectroscopic techniques, were used in the context of this research. Infrared images revealed that the underdrawing of the Annunciation mostly corresponded to the painted image but that two subjects — Annunciation and Adoration — were drawn over the prepared surface of the panel depicting the Adoration. This discovery is the first example of this procedure in Portuguese painting. The comparison with a third panel attributed to the painter, depicting another version of the Annunciation, allowed for the discussion of relevant technical procedures such as the use of cartoons, the responsibility for each main stage of painting creation and the reality of labour conditions in a regional market. The results contributed with material evidence to the scarce information of archival nature about the working methods of Portuguese mannerist painters.
Várias obras de pintura e desenho de Aurélia de Sousa (1866-1920) são estudadas a fim de se compr... more Várias obras de pintura e desenho de Aurélia de Sousa (1866-1920) são estudadas a fim de se compreender os contextos da Academia Portuense de Belas Artes e da Academia Julian e esclarecer algumas questões de proveniência e datação. As diferenças entre as duas fases são também discutidas com base no estudo dos materiais utilizados» designadamente as telas» os estratos preparatórios aplicados a esses suportes e as tintas.A set of paintings and drawings from Aurélia de Sousa (1866-1920) are studied in order to understand the contexts of the O porto Academy of Fine Arts and of the Academy Julian» as also to enlighten some provenance and date uncertainties. Differences am ong both periods are also discussed based on a scientific study upon the materiais used on the paintings» namely» canvases, ground layers and pigments.info:eu-repo/semantics/publishedVersio
Additional file 2 of Charcoal or black stone? Reconstructions as a tool to study the behaviour of dry underdrawing materials within the paint structure of sixteenth century panel paintings
Additional file 2: Appendix S2. Performance and appearance of the reconstructed underdrawing.
Additional file 1 of Charcoal or black stone? Reconstructions as a tool to study the behaviour of dry underdrawing materials within the paint structure of sixteenth century panel paintings
Additional file 1: Appendix S1. Materials and suppliers.
Problemas de conservación en pintura contemporánea: Estudio de dos pinturas de Pedro Cabrita Reis con contaminación por microorganismos
Conservación de arte contemporáneo: 11ª jornada, febrero 2010, 2010, ISBN 978-84-8026-430-3, págs. 271-282, 2010
Studies in Conservation, 2023
The palette used by the Portuguese painter Pedro Nunes (1586-1637) in the large panel depicting T... more The palette used by the Portuguese painter Pedro Nunes (1586-1637) in the large panel depicting The Descent from the Cross (460 × 304 cm) painted in 1620 for Évora's cathedral was investigated with a combination of the visual inspection of the paint surface and the analysis of the paint layers with microscopic, spectroscopic, and chromatographic techniques. Green earth and an orange artificial arsenic sulphide, two pigments identified for the first time in Portuguese paintings of the sixteenth and seventeenth centuries, were found to be abundantly used in large areas of the composition. The results further reveal the choice of a rich palette also containing lead-white, lead-tin yellow, ochre, vermilion, verdigris, smalt, azurite, vegetable carbon black, and a red lake made of brazilwood and cochineal. All the pigments were bound in an oil-based medium. The introduction of two pigments new to the Portuguese conventional palette is a direct consequence of the painter's training in Rome in the first decade of the seventeenth century.
ARTis ON
A Biblioteca Digital Ciarte (http://biblioteca.ciarte.pt), recentemente criada, tem como objectiv... more A Biblioteca Digital Ciarte (http://biblioteca.ciarte.pt), recentemente criada, tem como objectivos, por um lado, dar acesso à antiga literatura técnico-artística em português através de volumes em formato pdf resultantes de restauro digital propositadamente realizado e, por outro lado, disponibilizar informação sobre estas fontes fundamentais quer para o conhecimento das ideias, das técnicas e dos materiais de que são feitas as obras de arte e outros bens culturais, quer para a interpretação dos dados obtidos através de diferentes metodologias das Humanidades ou das Ciências. A apresentação aqui efectuada, além da divulgação da Biblioteca pelos interessados nestas fontes que são de difícil acesso, pretende igualmente expor os princípios que lhe estão subjacentes e as opções técnicas tomadas, que podem ser úteis para projectos semelhantes. O estreito e prolongado contacto com a grande diversidade de obras já digitalizadas serve de suporte à proposta de classificação tipológica desta...
Heritage Science, 2022
Reconstructions were used as a tool to investigate the use of charcoal and black stone as underdr... more Reconstructions were used as a tool to investigate the use of charcoal and black stone as underdrawing materials in sixteenth century panel paintings with white or off-white preparatory layers. Research was based on the examination of a group of sixteenth century panel paintings by the Portuguese Mannerist painter Francisco João (doc. 1558–1595) and his workshop. Analysis of the original underdrawing material in cross-sections, using microscopic and spectroscopic techniques was not always conclusive. Based on materials thought to be employed by Francisco João and on data collected from sixteenth and seventeenth century European technical treatises along with published analytical studies of panel paintings with white or off-white preparatory layers from this period, reconstructions were performed using charcoal (untreated and oiled—as described in contemporary literature) and natural black stone over different preparatory surfaces. Microscopic analyses of cross-sections from reconstr...
By means o f nitrogen adsortion, the textural characterization of 19 samples removed from sedimen... more By means o f nitrogen adsortion, the textural characterization of 19 samples removed from sedimentary d e p o s i t s ^ a lim estone cave with archaeological remains from the M edium Palaeolithic to the Present was carried out. The sim ilarity o f the isotherm s gives an indication o f the m ineralogical continuity o f the samples. The BET area is positively correlated with indicators o f the samples clay content, crystalline iron oxyhydroxides, phosphates, and m anganese oxyhydroxides in higher oxidation states, and negatively correlated with calcium carbonate and organic m atter contents. The BET area differences between two samples core cannot be interpreted as a result o f the m aterials age. The relationship between specific area and calcium carbonate is due to an effect o f the mass and, thus, the variation o f calcite along the profile is probably only a result o f physical processes. RESUMO Dezanove amostras do deposito sedimentar de uma gruta com vestfgios arqueologicos que...
Conservar Património, 2018
Conservar Património, 2017
What is the meaning of some of the marks incised in the back of old panel paintings? Resumo Algum... more What is the meaning of some of the marks incised in the back of old panel paintings? Resumo Algumas marcas incisas, de carácter tosco e caracterizadas por linhas a direito, entrecruzadas ou paralelas, incisas no reverso dos suportes de madeira de pinturas antigas de colecções portuguesas, de que se apresenta o respectivo levantamento bibliográfico, têm sido relacionadas com o fabrico ou a qualidade dos painéis, mas o facto de essas marcas não prosseguirem entre as tábuas de um mesmo suporte mostra que são anteriores à construção dos painéis. Como parece surgirem apenas sobre carvalho do Báltico e sobre superfícies não tratadas resultantes de débito por clivagem, deverão estar relacionadas com o abate das árvores e obtenção da madeira ou o seu comércio, como propõem J.-A. Glatigny e M. Rief, e não são marcas relacionadas com o fabrico dos painéis como têm sido consideradas.
Conservar Património, 2010
A primeira radiografia de pinturas em Portugal foi efectuada em 1923, por solicitação de Carlos B... more A primeira radiografia de pinturas em Portugal foi efectuada em 1923, por solicitação de Carlos Bonvalot, numa ocasião em que iniciativas semelhantes ocorriam noutros países. Tratou-se de um caso isolado que só teve continuidade em 1928 quando Roberto de Carvalho e Pedro Vitorino, também às próprias custas, iniciaram um projecto sistemático que deu origem a um número muito significativo de radiografias. De acordo com as interpretações feitas pelos seus autores e por Luís Reis Santos, algumas das radiografias punham em evidência significativos problemas de restauro e de autenticidade das obras. Entre 1934 e inícios de 1936, Carvalho e Vitorino foram proibidos de radiografar obras de museus do Estado, aparentemente a pretexto de os raios X poderem danificar as pinturas, mas mais ou menos na mesma ocasião foi adquirido equipamento de radiografia para o Museu Nacional de Arte Antiga, num processo, também pioneiro, em que esteve envolvido o conservador João Couto e o físico Manuel Valadares. Considerando a coincidência cronológica das duas iniciativas e o ambiente sócio-cultural da ditadura do Estado Novo que então vigorava em Portugal, a situação aparentemente contraditória é interpretada como uma forma de evitar a situação incómoda gerada pelas fortes críticas resultantes da interpretação das radiografias e controlar o surgimento de novos problemas a esse respeito.
Conservar Património, 2019
In the last few years, textiles have been increasingly valued as products of specific periods and... more In the last few years, textiles have been increasingly valued as products of specific periods and societies, reflecting the historical, social, artistic, economic and political contexts in which they were manufactured. Exceedingly resourceful, textiles have been essential for human life since time immemorial, being used and adapted in diverse applications and contexts. Due to their protective characteristics, by offering comfort and cover, but also as works of art or symbols of social status and economic power, textiles have been always highly regarded amongst all members of society [1]. Not only were they indispensable, but the inherent craftsmanship for the acquisition and preparation of the materials of which they were made, and subsequently, their production, were labour-consuming and subsequently expensive as well. All processes associated with the textile industry were often the foundations of entire communities, given the complexity and the lucrativeness of their manufacture. The demand and circulation of textiles reached its height during the Early Modern period, with the settlement of long-distance trade routes at a global scale that came to enrich local markets with the most sophisticated manufactures from all over the world [2, pp. 312-313]. This has been demonstrated by an increasing and diversified number of exhibitions, studies and publications dedicated to the field of textiles, confirming the timeliness and potential of this subject. Examples of these are exhibition catalogues, monographs and case studies on objects from archaeological sites or museum,
Iconography : Comparison of adsorbent materials for acetic acid removal in showcases
Data Revues 12962074 00090003 08000472, Sep 29, 2008
Applied Clay Science, 2015
Studies based on a scientific approach to materials and techniques used in Portuguese gilded reta... more Studies based on a scientific approach to materials and techniques used in Portuguese gilded retables from the Baroque are very scarce and focus particularly on works with erudite features and on the characterization of the superficial gold leaf. The conservation and appearance of gilded surfaces, however, depended on the qualities of the clayey ground layer underneath, which is the bole. Colour and texture are closely related to its mineralogical composition. Boles were healing clays. Red to orange varieties could also be used for gilding, usually agglutinated with animal glue when the gold surface was meant to be burnished. Armenian was the name used to identify the best quality material. Microsamples collected from erudite and popular gilded retables, respectively belonging to the city of Oporto and its rural surroundings, were selected for elemental and mineralogical characterization. It was intended to shed light on the characteristics of boles used in Portuguese retables and to understand if there are any differences between materials used in works of distinct artistic quality. Elemental analysis was performed through SEM-EDS. SR-XRD was used for phase identification, performed with a six-circle diffractometer at the DIFFABS beamline of SOLEIL Synchrotron. Portuguese clay standards of identifiable composition and provenance were also analysed. The results suggest that boles are mainly kaolinitic, with variable amounts of illite and smectite. Gypsum was used as an extender. Although the proportions of the main clay minerals are similar in erudite and popular works, in Oporto homogeneity is clearly higher.
The Materials and Techniques of Polychrome Baroque Wooden Sculpture: Three Works From Baião, Portugal
Int J …, 2010
Three polychrome wooden sculptures, made between the last quarter of the 17th century and the fir... more Three polychrome wooden sculptures, made between the last quarter of the 17th century and the first half of the 18th century, from a monastery in Northern Portugal, representing an episode of the Passion of Christ, were analyzed with three aims: to identify the materials and ...
Archaeometry, 2013
This paper provides a contribution to FTIR analysis of calcium sulphate-based grounds of painting... more This paper provides a contribution to FTIR analysis of calcium sulphate-based grounds of paintings when a mixture of compounds with different degrees of hydration is present. The study is based on the analysis with that technique, electron microscopy coupled with energydispersive X-ray spectrometry and X-ray diffraction of both the grounds of 16th-century Portuguese paintings and reference samples prepared with anhydrite and calcium sulphate dihydrate bound in an animal glue solution. It is shown that the interpretation of the degree of hydration of calcium sulphate ground samples using FTIR cannot be based solely on the study of the hydroxyl bands, as is usual in routine work, but that small deviations of the SO vibration bands are an important indicator of the presence of anhydrite in the grounds.
Italian Influence in a Portuguese Mannerist Painting (Part II): A Matter of Image or a Matter of Technique?
Studies in Conservation
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Papers by António João Cruz