Organic Matter and Pigments in the Wall Paintings of Me-Taw-Ya Temple in Bagan Valley, Myanmar

Abstract: Pagán is an ancient city located in Myanmar that is renowned for the remains of about 4000 pagodas, stupas, temples and monasteries dating from the 11th to 13th centuries. Due to a magnitude 6.8 earthquake in 2016, more than 300 ancient buildings were seriously damaged. As a part of the post-earthquake emergency program, a diagnostic pilot project was carried out on Me-taw-ya temple wall paintings to acquire further information on the materials and on their state of conservation. This article presents our attempts at characterising the painting materials at Me-taw-ya temple using non-invasive portable energy dispersive X-ray fluorescence (ED-XRF), portable Raman spectroscopy and micro-invasive attenuated total reflectance—Fourier transform infrared spectroscopy (ATR-FTIR), micro-Raman spectroscopy (-Raman), gas chromatography-mass spectrometry (GC-MS), polarized light microscopy (PLM) and environmental scanning electron microscope—X-ray energy dispersive system (ESEM-EDS) investigations with the aim of identifying the composition of organic binders and pigments. The presence of a proteinaceous glue mixed with the lime-based plaster was ascertained and identified by GC-MS. In addition, this technique confirmed the occurrence of plant-derived gums as binders pointing to the a secco technique. Fe-based compounds, vermillion, carbo

Lorenzo Lotto's painting materials: an integrated diagnostic approach

This paper presents the results of a comprehensive diagnostic investigation carried out on five paintings (three wood panels and two paintings on canvas) by Lorenzo Lotto, one of the most significant artists of the Italian Renaissance in the first half of 16th century. The paintings considered belong to 1508-1522 period, corresponding to the most significant years of Lotto's evolution. A wide array of non-invasive (reflectance spectrometry and Xray fluorescence) and micro-invasive analytical techniques (optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, micro-FTIR spectroscopy, micro-Raman spectroscopy, gas chromatography coupled with mass spectrometry and high performance liquid chromatography coupled with photodiode array detection and mass spectrometry) were applied in order to provide a large set of significant data, limiting as much as possible the sampling. This study has proved that Lotto's painting palette was typical of Venetian practice of that period, but some significant peculiarities emerged: the use of two kinds of red lakes, the addition of calcium carbonate and colourless powdered glass, the latter frequently found in pictorial and ground layers. Moreover, the integrated investigation showed that Lotto's technique was sometimes characterized by the use of coloured priming and multi-layer sequences with complex mixtures. Chromatographic analyses allowed to identify in all specimens: azelaic, palmitic and stearic acids, generally referring to the presence of drying oils. The extension of additional non-invasive examination to about 50 paintings by the same author, spanning from 1505 to around 1556, helped to verify the evolution in the use of some pigments, such as the yellow ones, where Pb-Sb yellow was used alongside Pb-Sn yellow. (C) 2016 Elsevier B.V. All rights reserved

The frieze of the Art of War in the Ducal Palace of Urbino: conservation issues, materials, and executive techniques

The frieze of the Art of War was originally positioned along the sides of the facade of the Ducal Palace in Urbino (Marche, Italy), and it is currently located in the palace’s Chancellery Room. The frieze, probably elaborated by Federico da Montefeltro around 1474, consists s of stone bas-reliefs illustrating a rich iconographic repertoire depicting numerous engineering machines and symbols related to the military and political spheres. The present work aims to deepen the knowledge of the Art War frieze and to clarify some doubts regarding the original shape of the bas-reliefs, the constituent material, and the executive technique; conservation issues were also considered. Polarized light microscopy observations were carried out on the stone materials, identifying the use of a packstone referable to the Calcare Massiccio A Formation (Hettangian-Lower Pliensbachian p.p.). This stone, locally known as Piobbico Travertine, was excavated in the Val d’Abisso quarries, part of the Umbria-Marche ridge. Ca-oxalates were detected by Fourier transform infrared analysis in the brownish patinas that mainly cover the surfaces of the bas-reliefs; they could be related to ancient conservation treatments and/or to biological agents. Regarding the execution technique, a thorough autoptic examination allowed for a better understanding of the original conformation of the bas-reliefs and the carving process. Stylistic and executive diferences in the execution of the same detail were observed in diferent bas-reliefs, confrming the activity of various sculptors. Diferent decay typologies were used to consider the debate regarding the original arrangement of the frieze on the facade, validating the most accredited hypothesis

Criteri e modalità di indagine diagnostica sui materiali naturali e artificiali

Identifying construction materials is the starting point for the recognition of degradation mechanisms and typologies and is essential for the correct planning of restoration interventions. In particular, mineral-petrographical and chemical studies on materials make it possible to examine a number of extremely important problems, such as those related to composition, origin, production technology and state of conservation. By identifying the types of degradation present, it is indeed possible to discover the causes leading to their formation and intervene to eliminate their effects with appropriate maintenance and restoration projects. In the case of the Church of St. Francis, the aim of the diagnostic project was to obtain information on the nature and origin of the natural stone materials, the techniques used to prepare artificial stone materials (brick) and the state of conservation. Mainly brick is used on the façade, with colours ranging from red to pinkish red. Stone is used only to a limited extent for the columns, capitals, arches, bases, steps and shelves. The state of conservation of the façade varies with widespread deposits, black and white areas and phenomena of erosion. Extensive con- sistent yellowish deposits, cracking, gaps, dripping, engravings and graffiti are also present. Various architectural elements had been replaced, above all at the bottom of the façade, creating a certain irregularity in the interpretation of the structure. The diagnostic project entailed the collection of representative micro-samples of the structure investigated, without altering the formal and aesthetical appearance in any way. The specimens underwent the following studies: optical microscopic (OM) mineral-petrographical examination and x-ray diffractometry (XRD) mineralogical analyses. The investigations carried out on natural stone materials led to the identification of different local lithotypes: Bugarone, Red Shingle and Sandstone of St. Hippolytus. Although the colour of the bricks varied to some extent, their composition was substantially similar. Deposits and black crusting consisted mainly of air particulate, gypsum, calcite, quartz and opaque minerals. The analysis of the state of conservation of the Church of St. Francis demonstrated a particularly critical situation requiring urgent restoration interventions, taking into account the nature of the materials, their characteristics and the surrounding environment. A knowledge of materials and degradation processes may help to develop specific conservation intervention systems in that this permits identifying the most appropriate products and technologies, from those available, for specific problems, preventing situations of incompatibility and ensuring their duration and resistance in time

La tecnica pittorica di Giovanni Santi in Giovanni Santi e la corte di Urbino

La professionalità di Giovanni Santi pittore rimane ancora fortemente legata alla tradizione, sia per l’impostazione grafica delle sue opere sia per i materiali usati, ma ricettiva rispetto alle nuove tendenze della pittura come l’impiego dell’olio siccativo e, come queste ricerche dimostrano, a soluzioni sperimentali per la pittura italiana come l’uso della polvere di vetro. Trovandosi a operare in un luogo che fu crocevia di scambi anche artistici di primaria importanza, con contatti diretti con artisti italiani e d’oltralpe del calibro di Piero della Francesca e di Giusto di Gand, per citarne un paio, e in un momento cruciale rispetto all’elaborazione anche tecnica che porterà poi alle novità del Cinquecento, diventava interessante occuparsi dei suoi metodi esecutivi, anche considerando che si trovò a gestire un’importante bottega operando su molteplici supporti. Un’estesa campagna analitica, con tecniche di indagine principalmente di tipo non invasivo e, in qualche caso oculatamente scelto, di tipo micro-invasivo, è stata infatti condotta a scopo conoscitivo e conservativo su ventotto opere di Giovanni Santi che coprono l’intero periodo di attività dell’artista e rappresentano le differenti tipologie di manufatti realizzate nella sua bottega per svariate committenze, dalle grandi pale, ai dipinti di piccole e medie dimensioni, alle pitture murali

I materiali e la tecnica pittorica della Comunione

Le analisi condotte sulla Comunione degli apostoli in vari momenti e infine con maggior dettaglio in occasione di questa pubblicazione, ci permettono non solo di approfondire i materiali e la tecnica pittorica impiegata da Giusto di Gand, ma anche di raffrontarla a livello tecnico con le tavole degli Uomini Illustri, conservate in parte nel medesimo palazzo urbinate e in parte al Louvre, con le quali presenta numerose similitudini sia nel sistema di realizzazione della carpenteria1 sia nelle modalità pittoriche, indagate in dettaglio in anni recenti. Il supporto ligneo della Comunione è costituito da quattordici assi di pioppo disposte in verticale, di larghezza variabile e spessore elevato, intorno a 4 cm. Lo strato preparatorio applicato sulle tavole è a base di gesso e colla, come evidenziato dalle analisi svolte su microprelievi. Il disegno – per le cui caratteristiche si rimanda al saggio precedente – è realizzato a pennello direttamente sulla preparazione, con un inchiostro che è risultato contenere particelle nere di origine animale (nero d’ossa/avorio), analogamente a quanto emerso negli Uomini Illustri. Le più recenti indagini condotte sulla Comunione degli apostoli, sia di tipo non invasivo in situ – consistenti in spettrometria di riflettanza (vis-RS) e spettrometria dei raggi X in dispersione di energia (ED-XRF o XRF) e microscopia ottica – sia micro invasivo – mediante studio di sezioni stratigrafiche hanno permesso di aggiungere ulteriori elementi alla conoscenza della tavolozza pittorica impiegata rispetto a quanto già riportato in letteratura6 e hanno confermato l’utilizzo di olio siccativo come legante, tipico dell’arte fiamminga