Materials and techniques in the pictorial oeuvre of Lucio Fontana

Abstract

The painting materials used by Lucio Fontana were investigated through the analysis of 28 Spatial Concept works created between the early 1950s and the artist's death in 1968. The pictorial media were analyzed by means of numerous techniques including Fourier transform infrared spectroscopy, pyrolysis-gas chromatography–mass spectrometry, scanning electron microscopy, and X-ray fluorescence. This study has provided a more complete understanding of the artist's technique, as it was found that Lucio Fontana had already begun experimenting with new synthetic pictorial and binding media such as alkyds and polyvinyl acetates at the beginning of the 1950s, and polyesters during the early 1960s. Although he never abandoned the use of commercial oil paints, Fontana's application of these new materials continued in an infinitely varied search for innovative expressive effects. The characterization results explain the physical and mechanical properties of the paint layers, and may be correlated with the conservation state of the works analyzed. All the results have been compiled and are discussed together with the artist's practices and their evolution over time.     

Jack Chambers’ mixed media paintings from the 1960s and 1970s: Painting technique and condition

Abstract

This study describes the examination and analysis of four mixed media paintings from the 1960s and 1970s by Canadian artist Jack Chambers (1931–1978). The documentary evidence about his materials and methods is summarized and compared with the results of analysis of multilayer paint samples. The combination of Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) allowed the components of the paint media to be characterized: ortho-phthalate alkyd resins, iso-phthalate alkyd resins, drying oils, dammar, Pinaceae resin, and turpentine were identified in varying proportions. Many pigments and fillers were identified by FTIR and Raman and are enumerated. The effect that Chambers’ complex technique has had on the aging and degradation of the paintings is discussed. The severe cracking of the paint layers in one of the four paintings may be the result of a high proportion of dammar and turpentine diluent mixed with the alkyd paint and may also be related to the type of alkyd resin medium. Different history and environmental conditions may also be factors.     

The materials and techniques used in the paintings of Francis Bacon (1909–1992)

Abstract

Materials from 38 paintings by Francis Bacon (1909–1992), including 21 complete works and 17 partially destroyed canvases are investigated. Observations are made of the artist's technique and details are compiled of the supports used. Samples of paint and priming were taken for analysis using polarized light microscopy, Fourier transform infrared spectroscopy (FTIR), gas chromatography–mass spectrometry (GC–MS), pyrolysis–GC–MS (Py–GC–MS), and scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM–EDX). Analysis of priming layers appears to show that the priming composition correlates well with particular ranges of dates. A fairly limited range of materials are found, with many of the same pigments found in works spanning Bacon's career, though other pigments were introduced at different stages in his career. Oil paints were used consistently for the painting of figures, but household paints were increasingly used in backgrounds from the 1960s onwards. A variety of different synthetic media are found in later works, including household acrylic paints and spray paints. Increased knowledge of Bacon’s materials is expected to be of great value to conservators caring for the work of this highly significant artist, and is already helping in the authentication of works attributed to him.     

A Technical Analysis of Three Paintings Attributed to Jackson Pollock

Abstract

Three paintings from a group of thirty-two attributed to Jackson Pollock (1912–1956) were examined at the Harvard Art Museums. Paint samples were examined using Raman spectroscopy, scanning electron microscopy–energy dispersive X-ray spectrometry (SEM-EDX), laser desorption ionization time-of-flight mass spectroscopy (LDI-MS), Fourier transform infrared spectroscopy (FTIR), pyrolysis–gas chromatography–mass spectrometry (py-GCMS) and carbon-14 (C-14) dating. Carbon-14 dating detected no 'bomb' carbon from atmospheric atomic testing. All three paintings contained pigments and media available only after Pollock's death, including PR 254, PY151, and an emulsion copolymer of n-butyl methacrylate and iso-butyl methacrylate.     

The conservation of the mudejar templete at the Royal Monastery of Our Lady of Guadalupe,Extremadura (Caceres), Spain

Abstract

This paper presents the program initiated to conserve the templete in the Mudéjar Cloister in the Royal Monastery of Our Lady of Guadalupe. The program included evaluation of the original materials, development of repair materials and design of a conservation program for the templete. The paper concentrates on the analysis and conservation of the stuccos of the templete, which is a typical mudéjar-style structure of molded brick with an exterior stucco finish. Samples of stucco from the templete were analyzed by microscopy, both reflected and transmitted light; acid digestion (gravim～tric analysis); water vapor transmission rate; and Fourier transform infrared spectroscopy. Samples of pigments and salts were identified by microchemical methods. Data from these analyses were used to develop a replication stucco mix and a grout mix that would be physically and chemically compatible with the existing materials. The process of developing the mixes is described. Application of these materials to the conservation of the templete is outlined. The stucco mix was used for repairing the upper stage of the templete, which was largely devoid of its original stucco coating, and the grout was used to stabilize the stuccos of the base, which were largely intact but detached from the underlying brick.     

Investigation of the Er:YAG Laser at 2.94 μm to Remove Lichens Growing on Stone

Abstract

The analysis of the surface ablation of the removal of lichens from stone by use of a free-running pulsed Er:YAG laser (erbium-doped yttrium, aluminium, garnet crystal) at a wavelength of 2.94 μm demonstrated the complete destruction of the lichen cell wall. In this paper these results are confirmed, and experiments are described which seek to determine the physical/chemical mechanism of the ablation process using pyrolysis gas chromatography–mass spectrometry (pyrolysis GC-MS), highperformance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR) and fluorescence microscopy.     

Notes

Abstract

Remnant dye on an excavated textile has been identified using a Fourier transform infrared microscope on a scale far below that which is possible by extractive techniques. The sample requires minimal preparation, a single fibre being sufficient to obtain a useful signal. A spectral data library of fibre, dyes and mordants has been built into the computer analysis program and four separate algorithms within the search facility are used to make the identification. The method is quick and may avoid some of the problems caused by masking of the infrared signal due to sample contamination during burial.     

Enamel insert restorations on Limoges painted enamels: A study on a remarkable nineteenth-century restoration technique with particular attention to the original paillon designs

Two sixteenth-century Limoges painted enamel plaques by Léonard Limosin in the collection of the J. Paul Getty Museum, Los Angeles, show a remarkable restoration technique consisting of separately enameled pieces that have been inserted into areas where original enamel was lost. A detailed investigation of the two plaques brought information about this former restoration method and the materials used. Investigation included optical microscopy, UV-A examination, and X-radiography for identification and mapping of the insert restorations, scanning electron microscopy with energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and gas chromatography-mass spectroscopy for analyzing organic restoration material as well as X-ray fluorescence for studying the enamel compositions. A survey of six other Limoges painted enamel collections in the USA was carried out, which revealed many more of these insert restorations and indicated particular damages related to the so-called paillon designs on silver or gold foils. A literature review was undertaken focusing on possible causes of the damage as well as on persons and workshops that may have executed the insert restorations.     

Artificial paint or patina on the sandstone of the Ramos Gate at the Catedral Nueva in Salamanca,Spain

Abstract

Many buildings of historical importance in Salamanca are of sandstone. Over time, this sandstone becomes covered with a coat of natural patina which makes the whole building appear golden in colour. Apart from this patina, another artificial reddish patina or paint can be observed on some of the buildings, mainly on the ornamentation of portals in the flamboyant Gothic and Plateresque styles. The samples in this study come from the Ramos Gate of the Catedral Nueva in Salamanca, Spain. The inorganic and organic compounds were analyzed using the following techniques: scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR) and gas chromatography/mass spectrometry (GC/MS). The results showed that the inorganic compounds are clays and iron oxides, while the organic materials are albumin, traces of collagen (serving as binding material) and small amounts of fat. For the sandstone, this coating proved to be an excellent protection against external weathering agents.     

Disfiguring organic residues on industrially produced sheet metal coupons simulating copper and brass works of art by Donald Judd: Attenuated total reflectance Fourier transform infrared spectroscopy analysis and treatment recommendations

Abstract

The Minimalist work of Donald Judd exemplifies modern and contemporary works of art that utilize the appearance of bare metal as an integral component of the artist's intent. Decades after fabrication, disfiguring patterns have appeared on the surfaces of many such works. These patterns are not related to the formation of tarnish or other corrosion effects caused by improper storage, display, or transportation and handling; rather, they are associated with the initial processing of the metal sheets and subsequent fabrication of the art objects. Due to the challenges of obtaining analytical data directly from works of art, the authors present results from industrial sheet metal coupons prepared to simulate materials and techniques used in Donald Judd's copper and brass artworks. Attenuated total reflectance Fourier transform infrared spectroscopy carried out on each side of 55 coupons indicated the presence of organic materials such as long-chain aliphatic hydrocarbons, esters, and ethers, consistent with the types of compounds used in industrial lubricants. In addition to conducting the first systematic instrumental analysis of these residues, the authors propose the use of specific solvents for their removal as an alternative to abrasive methods, which cause removal of original surface from the objects.     

Mineralogical,Chemical, and Thermal Characterizations of Historic Lime Plasters of Thirteenth–Sixteenth-century Daulatabad Fort,India

Iron ore as pozzolanic filler is an uncommon constituent of historic plaster rarely reported in any research. This paper presents one such study from western India where hematite instead of crushed bricks was identified as admixture in thirteenth–sixteenth-century CE Mughal masonry lime works of Daulatabad Fort. The outer/inner coat plasters from different locations of the fort were examined for morphological, mineralogical, chemical, and basic physical properties. The analytical investigative study was performed by optical microscopy, sieve analysis, X-ray fluorescence, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, SEM-EDX, and thermal analyzer. Although the plaster is dominantly made of micritic calcite and aggregate, incorporation of gypsum in the outer and inner coats has been detected and probably acted as a second binder. Cannabis sativa was mixed in the plaster, pointing to the knowledge of hempcrete technology by the makers of Daulatabad Fort. This investigation has now provided essential information with enough precision about this historic plaster for formulation of compatible repair materials essential for the site restoration.     

SOME ASPECTS OF THE CONSERVATION OF WORKS OF ART IN BUILDINGS OF NEW CONCRETE

Abstract

This paper deals with the materials used in conservation treatments in the first half of the twentieth century for the preservation and consolidation of wooden art objects from the Saxony region in Germany. The use of such materials must be seen as early attempts to find a conservation treatment for wood. The documentation of conservation treatments provides a reference to the application of oils and oil–resin mixtures. The results from the chemical analysis of samples of historic preservatives from the beginning to the middle of the twentieth century (so-called 'Puckelin') carried out by gas chromatography–mass spectrometry (GC-MS) and Fourier transform infrared (FTIR) analysis confirm the use of tung oil as a drying oil, whereas the use of linseed oil cannot be excluded. Colophony and, probably, amber varnish were used as resinous constituents. There are indications that a conservation material dating from the second half of the twentieth century most likely contained rapeseed oil.     

Climatically Induced Degradation Processes in Conserved Archaeological Wood Studied by Time-lapse Photography

ABSTRACT

Samples of conserved archaeological wood of different ages, origins, and conservation histories were aged in a climate chamber for seven months, while the humidity alternated between 30% RH for 12 hours and 80% RH for 12 hours at a constant temperature of 30°C. Photographs were taken once every hour, which enabled the creation of a time-lapse movie. Some samples degraded visibly, whereas others were unaffected. Most of the samples were robust and would be able to survive well even in a very poor museum climate. Among the sensitive samples, three types of degradation were identified, namely disintegration, pyrite oxidation, and efflorescence of white crystals. Disintegration was ascribed to dimensional changes caused by the RH alternations in very fragile wood. The white efflorescence was interpreted as the recrystallization of an alum-associated substance, possibly mercallite (KHSO₄). The pyrite oxidation was observed as the efflorescence of a thick yellow, grey, and green powder. Characterization of selected samples was performed using X-ray fluorescence spectrometry, X-ray diffraction spectrometry, scanning electron microscopy with energy dispersive X-ray spectroscopy, inductively coupled plasma – optical emission spectroscopy, Fourier transform infrared spectroscopy, ionic conductivity – liquid chromatography, and pyrolysis-gas chromatography-mass spectrometry with in situ silylation using hexamethyldisilazane.     

A seventeenth century Japanese painting: Scientific identification of materials and techniques

A Japanese painting on paper, in the form of a horizontal scroll from the Stibbert Museum in Florence, is being treated at the ISCR Paper Conservation Laboratory. The scroll, entitled Bamo Dōi-zu represents 33 different types of horses. Although there is no author's seal, it has been attributed to the famous Japanese artist, Kanō Sansetsu (1589–1651). Before conservation treatment, the artefact underwent technical and scientific examination in order to identify its materials and determine its conservation condition. As sampling paint layers from paintings on paper is extremely invasive, non-destructive techniques such as X-ray fluorescence spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and spectrophotometry were employed. Several points from the paper support were analysed: the metal-leaf decorations, the seals and calligraphy, as well as the painted horses. Results detected and revealed a very simple palette: cinnabar (or its synthetic equivalent vermillion), shell white, carbon black, and the organic yellow gamboge. Pure gold and silver leaves were used for decorating the frontispiece. Useful information was obtained from the paper support and on its conservation conditions. Micro-destructive analyses were also performed on a few paper fragments for microscopic and scanning electron microscope equipped with an X-ray probe analysis. Results showed that materials and techniques are consistent with the Kanō School period.     

A study of the effects of conservation treatment on the Fanshawe Archive

Abstract

Valence House Museum (Dagenham, England) has, since 1963, housed not only a large collection of Fanshawe family portraits but also a very rich family archive which comprises estate and private papers from the sixteenth to the twentieth centuries of at least two branches of the family. Of national and international interest are the papers of Sir Richard Fanshawe (1608-66) relating to his three embassies to the Iberian peninsula in the 1660s. Three documents from this collection were taken for conservation and treated using both aqueous and non-aqueous methods of deacidification. Prior to treatment, the papers were characterized using the techniques of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), electron spectroscopy for chemical analysis (ESCA or XPS), thermogravimetry (TGA) and thermomechanical analysis (TMA and DLTMA). Measurements showed that the three papers were similar in composition and were basically cellulosic materials with varying trace levels of Fe and Cu impurities. All three documents contained iron gall ink; the ink of the Dublin letter had an additional feature in the form of small bright specks which were characterized as a form of mica. After conservation treatment the papers were examined using the above techniques in an attempt both to determine and to quantify any changes which had occurred during the treatment process. Scanning electron micrographs showed that pronounced changes had occurred in the surfaces of the treated papers. With XPS it was possible to measure the change in the surface composition of the papers which occurred on treatlp.ent. It was also found that the treatment reduced the thermal stability of the papers in all three cases.     

Light-induced color changes and chemical modification of treated and untreated chestnut wood surface

Abstract

The aim of this work is to study the surface modifications of chestnut (Castanea sativa Mill.) wood by reflectance spectrophotometry and Fourier transform infrared spectroscopy (FTIR) in order to understand the mechanisms that cause changes and to suggest possible solutions to avoid degradation phenomena. The experimental data were statistically treated to evaluate their significance. Concerning the surface protection of wood, starting from the results obtained by testing different commercial products, attention was focused on a novel organic preservative/consolidant product (Linfoil^®) that has attracted great interest in the field of conservation of wooden artifacts. Color monitoring showed that wood surface color undergoes an important variation due to photoirradiation, occurring within the first 24 hours and mainly due to L* decrease and b* increase. Though the protective treatment modifies wood color, nevertheless the product tested seems to protect the wood surface by reducing photoyellowing. FTIR analysis indicated that irradiation caused the degradation of lignin and increased the concentration of the chromophore groups on the wood surface. Changes in the chromaticity coordinates can be linked to the degradation of lignin and to increase of the concentration of carbonyl groups.     

Investigation of Effects of Fumigants on Proteinaceous Components of Museum Objects (Muscle,Animal Glue and Silk) in Comparison with Other Non-chemical Pest Eradicating Measures

Abstract

Fumigant effects on protein-based materials were examined and compared with those of non-chemical pest-eradicating measures. The responses to six fumigants – methyl bromide, methyl iodide, ethylene oxide, methyl bromide/ethylene oxide mixture, propylene oxide and sulfuryl fluoride – were examined with two controlled atmospheres and a range of thermal treatments, using protein electrophoresis, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermal microscopy (T_mic), thermal gravimetric analysis (TGA), amino acid analysis and X-ray fluorescence (XRF) spectrometry. A model soft-tissue protein, freeze-dried chicken muscle, was shown to be affected by some fumigants, especially methyl bromide, methyl iodide and sulfuryl fluoride (Vikane^®). This is the first detailed evidence of chemical alterations of a protein material by fumigants under the common treatment conditions for museum use, especially showing a possibility of protein modification by purer grade sulfuryl fluoride whose definite mechanism of toxicity is still unknown. Residual bromine and iodine were clearly detected by XRF in the muscle specimen that had been fumigated with either methyl bromide or methyl iodide respectively, even after a single fumigation several years earlier. On the other hand, significant change in characteristics of animal glue and new and deteriorated silk textiles were not detected. However, residual bromine and occasionally iodine also were detected in the glue and silk samples fumigated by methyl bromide or methyl iodide several years earlier.     

A comparative study of wall painting materials and techniques used in fifteenth century Austria by Frederich of Villach and his followers

One of the most important artistic circles in the first half of the fifteenth-century in Austria was the so-called ‘Older Villach's workshop’, founded by Frederic of Villach, a painter who was considered a master of fresco technique. A technical study was made of a number of wall painting cycles by the workshop of Frederic of Villach, first, to gain a broader knowledge of the painting techniques employed, and second, to allow comparison with a further group of wall paintings in Slovenia, which are stylistically related to this workshop and have been studied previously. Of special interest were artworks attributed to Frederic's son Johannes of Ljubljana and a number of other anonymous painters that show important similarities to Frederic's works. Samples of plasters and pigments were analysed by optical microscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. An important difference in the composition of plasters was discovered between the selected artistic groups. The palette used comprised predominantly earth and other mineral pigments. The construction of the paintings from incisions and preparatory drawings to the final modelling is basically similar and shows workshop connections. The principal painting technique was a fresco. The results contribute to a wider knowledge concerning the materials and techniques employed in gothic wall paintings in the Alpine region and offer new information that can be used to inform the future conservation of these selected wall paintings.     

The terracotta modelli of Palazzo Venezia in Rome: Investigation of the constituent materials for fundamental knowledge and to aid conservation decisions

This work presents the results of the investigation carried out on a group of terracotta sculptures (modelli) (sixteenth to eighteenth century) belonging to the extraordinary collection of Palazzo Venezia in Rome. The study, the diagnostic analysis, and the conservation work, were possible thanks to the grant supplied by the Getty Foundation of Los Angeles and by the bank Intesa San Paolo. The terracotta modelli had a practical function as they were of great use as sketches to the creation of the final masterpieces or as models for restoration. As a consequence, the terracotta models allow reconstructing the creative process of artists and restorers, fundamental to outlining the ancient workshop production. X-ray fluorescence spectroscopy, micro-stratigraphic investigation, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy were chosen as useful techniques to study the morphology and composition of the surface-painted layers. Usually the surfaces were painted in order to simulate the materials of the sculpture for which the model was created, for example lead white was used to obtain a white surface simulating marble. But, often the models were re-painted to make them more attractive for the antique trade. So, several pigments have been found on the surfaces such as zinc white, Prussian blue, chrome yellow, and mono-azo pigment. In some cases, the characterization of the surface paintings was particularly important to the final decision about removing or leaving the surface paint in place.