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1.
《文物保护研究》2013,58(1):54-55
Abstract

Before commencing the conservation treatment of a fifteenth-century coffered ceiling in the convent of Santa Fe, Toledo, the painting materials were analyzed. Elemental analysis of the pigments was carried out by XRF spectrometry. Cross-sections were made of the samples for optical microscopy. The binding media and the varnish were identified by gas chromatography, by analyzing the fatty acids, terpenes and amino acids. Once the painting had been studied, consolidation treatment was applied using different materials according to the solubility of the paint layers. Animal glue was mainly used, and Paraloid B-72 to a lesser extent, as a preliminary to the structural reinforcement of the support.  相似文献   

2.
《文物保护研究》2013,58(1):22-26
Abstract

Very small paint samples from Cosimo Tura's ‘The Annunciation with Saint Francis and Saint Louis of Toulouse’ were submitted to amino acid analysis in order to determine the nature of the binding media. The four panels appeared to have been painted with egg tempera, and showed extensive localized deterioration in the blue areas but not in the other coloured areas. Following the Picotag method, the samples were hydrolyzed in an acid vapor, derivatized with iso-thiocyanatobenzene, and analyzed using reversed phase high pressure liquid chromatography (HPLC). Amino acid analysis demonstrated that the red and brown areas were painted using egg yolk as the binding medium, while the blue areas were painted with animal-skin glue (distemper). Analysis of the green paint indicated a mixture of egg yolk and glue. The use of these techniques makes it possible to identify proteinaceous materials in art objects from samples in the microgram range.  相似文献   

3.
《文物保护研究》2013,58(4):145-161
Abstract

For the study of Italian paintings and their techniques the examination of the binding media (glue, egg, oil) has considerable importance, but with the usual scientific methods of analysis the results have never been conclusive. Each sample may include more than one layer of paint and many constituents; egg yolk alone contains protein, oils, cholesterol. In the present project, in order to identify these diverse materials and also to eliminate interference from contamination (glue, wax or oil) used in later restoration processes, it was decided to mount original paint samples, including a bit of the ground, as cross-sections in a polyester resin embedding material and then to make the constituents visible under the microscope by using selective staining techniques. Only in this way could the foreign materials be distinguished from the original and the structure of the original layers be understood. Finally, other tests such as the fluorescent antibody technique and thin-layer chromatography could be applied to confirm the results of the staining. In removing over 500 specimens fronl paintings in the Walters Art Gallery precautions were taken to assure sample authenticity, and during the testing at the University of Michigan careful methods of standardization and control were devised, using both fresh and old samples of egg tempera and oil. Two stains, Ponceau S for protein and Sudan Black B for oil, provided the most workable means of identifying the binding media in the majority of the samples studied. A final report will have to await correlation of the material, but certain observations may be made at this stage: (a) 14th century, in primarily tempera paintings a limited use of oil was found associated with a specific green pigment, copper resinate; (b)15th century, the majority of the paintings were entirely of egg tempera, but layers containing oil in the underpainting or in the above-mentioned copper green occurred more frequently; (c)16th century, egg tempera was not replaced by oil, but both were used in a complex layering technique, the media varying layer by layer and area by area; (d)17th century, the mixed technique gradually declined, but egg tempera continued to be associated with the painting of flesh and occasional highlights.  相似文献   

4.
Moisture is a driving factor in the long-term mechanical deterioration of canvas paintings, as well as for a number of physico–chemical degradation processes. Since the 1990s a number of publications have addressed the equilibrium hygroscopic uptake and the hygro-mechanical deformation of linen canvas, oil paint, animal glue, and ground paint. In order to visualise and quantify the dynamic behaviour of these materials combined in a painting mock-up or reconstruction, we have performed custom-designed experiments with neutron radiography and nuclear magnetic resonance (NMR) imaging. This paper reports how both techniques were used to obtain spatially and temporally resolved information on moisture content, during alternate exposure to high and low relative humidity, or in contact with liquids of varying water activities. We observed how the canvas, which is the dominant component in terms of volumetric moisture uptake, absorbs and dries rapidly, and, due to its low vapour resistance, allows for vapour transfer towards the ground layer. Moisture desorption was generally found to be faster than absorption. The presence of sizing glue leads to a local increase of moisture content. It was observed that lining a painting with an extra canvas results in a damping effect: i.e. absorption and drying are significantly slowed down. The results obtained by NMR are complementary to neutron radiography in that they allow accurate monitoring of water ingress in contact with a liquid reservoir. Quantitative results are in good agreement with adsorption isotherms. The findings can be used for risk analysis of paintings exposed to changing micro-climates or subjected to conservation treatments using water. Future studies addressing moisture-driven deformation of paintings can make use of the proposed experimental techniques.  相似文献   

5.
To date, a limited number of aqueous conditions have been tested experimentally as potential cleaning reagents on modern acrylic paint films. Those assessed have tended to extract measurable quantities of paint film components and distort the paint films physically. In this paper the results of a series of experiments designed to examine pH, conductivity, and specific ion effects of potential aqueous cleaning solutions on a series of commercial acrylic paints are reported. A three-dimensional microscopic technique was used to characterize the physical (volume and surface roughness) changes and liquid chromatography-tandem mass spectrometry was used to characterize the chemical (extracted surfactant) changes following paint film exposure to the aqueous solution. The tested paint films in this study clearly exhibit an isotonic point below which swelling and extraction is significant, and above which the swelling and extraction is diminished. Manipulation of conductivity and the ionic species in solution can reduce both the physical film changes and surfactant extraction from acrylic paint films; while pH appears to be of limited use in controlling aqueous cleaning effects. Moreover, there seems to be a specific ion effect for both swelling and de-swelling in acrylic paint films that can be rationalized through the Hofmeister Series.  相似文献   

6.
ABSTRACT

Composition, microstructure, and binding media of the decorative earthen plaster fragments from the Buddhist cave temple of Bezeklik (fifth–fourteenth century CE), China, were analyzed by X-ray fluorescence, X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analysis, Fourier-transform infrared spectroscopy, sieve analysis, and other methods. In addition, gas chromatography–mass spectrometry was used for identification of the organic adhesive found mixed in the earthen plaster. Studies indicated the presence of proteinaceous material, mainly beeswax, with animal glue, pine resin, and plant sterol mixed in the earthen plaster as the biopolymer. The organic additives improved the basic qualities of the mud by acting as stabilizers, hardeners, and water proofers. The loamy sand soil sourced for Bezeklik plasters shows low cohesion and disaggregation of grains occurred for want of clay-sized particles in the plaster. Due to frequent handling and transportation, the fragments are now showing distress in the form of loss of earthen support and paint layers. Based on the analytical findings, traditional binders such as sepiolite clay, slaked lime, and fish glue were introduced and fragments consolidated for display.  相似文献   

7.
《文物保护研究》2013,58(4):225-241
Abstract

This paper describes the application of pyrolysis–gas chromatography–mass spectrometry (PyGCMS) to the characterization of an extensive range of synthetic paint types. Household and industrial paints, both of which have been formulated with polymers such as alkyd, polyvinyl acetate (PVA) and nitrocellulose, are included in this study, in addition to the acrylic solution and acrylic emulsion paints that were made specifically for the artists' market. The pyrograms obtained by PyGCMS were characteristic to each paint type and their principal diagnostic features are discussed. Apart from using the mass spectra produced by electron impact (EI) to confirm the identity of every peak, two additional analytical features of the mass spectrometer were shown to be particularly useful in this study. Chemical ionization (CI) was used to assist with the identification of unknown peaks through molecular weight determination. Selected ion current (SIC) monitoring, where the mass spectrometer only scans for specific masses, was successfully used for the detection of peaks of low intensity or those hidden by a more abundant material with a similar retention time.  相似文献   

8.
《文物保护研究》2013,58(4):241-249
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.  相似文献   

9.
《文物保护研究》2013,58(2):44-108
Abstract

Thomas Bardwell (1704–67), an English portrait painter, wrote a technical treatise entitled The Practice of Painting and Perspective Made Easy which was published in 1756. The section on painting deals exclusively with the oil technique and may be considered one of the most original productions of its kind written in England. A total of 153 paint samples were taken from 15 of Bardwell’s paintings dating between 1740 and 1766, the better part of his active career. Through cross-sections, and likewise numerous analyses, made from these paint samples it was possible to reconstruct Bardwell’s actual practice. This in turn could be compared with the suggested technique as explained in his book. Bardwell’s actual practice follows his written advice rather closely; however, in general it was discovered to be less complicated.  相似文献   

10.
A great number of Central Asian wall paintings, archeological materials, architectural fragments, and textiles, as well as painting fragments on silk and paper, make up the so called Turfan Collection at the Asian Art Museum in Berlin. The largest part of the collection comes from the Kucha region, a very important cultural center in the third to ninth centuries. Between 1902 and 1914, four German expeditions traveled along the northern Silk Road. During these expeditions, wall paintings were detached from their original settings in Buddhist cave complexes. This paper reports a technical study of a wall painting, existing in eight fragments, from the Buddhist cave no. 40 (Ritterhöhle). Its original painted surface is soot blackened and largely illegible. Grünwedel, leader of the first and third expeditions, described the almost complete destruction of the rediscovered temple complex and evidence of fire damage. The aim of this case study is to identify the materials used for the wall paintings. Furthermore, soot deposits as well as materials from conservation interventions were of interest. Non-invasive analyses were preferred but a limited number of samples were taken to provide more precise information on the painting technique. By employing optical and scanning electron microscopy, energy dispersive X-ray spectroscopy, micro X-ray fluorescence spectroscopy, X-ray diffraction analysis, and Raman spectroscopy, a layer sequence of earthen render, a ground layer made of gypsum, and a paint layer containing a variety of inorganic pigments were identified.  相似文献   

11.
《文物保护研究》2013,58(3):195-208
Abstract

Pyrolysis–gas chromatography was applied to the characterization of synthetic organic pigments. On pyrolysis, azo pigments and phthalocyanine blue yield characteristic fragments. These pyrolysis products were identified, and the mechanism of decomposition was studied. In the case of paint samples, the main pyrolysis products derive from the medium, although the presence of additional peaks enables azo pigments and phthalocyanine blue to be characterized. Some examples of the analysis of artists' paints are given and the peaks are identified. The main limitation of this technique is that it is impossible to detect chemically and thermally stable pigments, or inorganic components.  相似文献   

12.
《文物保护研究》2013,58(3):223-225
Abstract

Sophisticated modern instruments and methods can contribute to the preservation of national and cultural heritage. Modern analytical methods such as chromatography, spectrometry and densitometry are extremely useful, particularly for the analysis of rare works of art from which only very small samples are available. This study describes the identification of the binding medium from a 200-year-old fragile silk banner using thin layer chromatography and video densitometry. The method involved the separation and identification of pure amino acids, vapour-phase hydrolysis of both the reference protein materials and the sample from the banner, and thin layer separation of the components. The separation was achieved using cellulose plates and a mixture of butanol, acetic (ethanoic) acid and water as eluent. The plates were sprayed with ninhydrin solution and then recorded by a Camag video densitometer system. The chromatograms with coloured spots were recorded under white light using a highly sensitive charge-coupled device (CCD) colour video camera. Images were acquired, processed and archived with Video Store 2 version 2.30 documentation software, and analysed using the Vista Scan program. The results for the unknown protein binder were compared with those for the standards. The experimental data identified the proteinaceous binder as an animal glue.  相似文献   

13.
《文物保护研究》2013,58(4):195-206
Abstract

The investigation of materials found in Bacon's studio is reported. The contents of the studio are examined and interpreted to identify the materials and colours most favoured by Bacon, and the range of media used. A small number of colours appear to have been heavily used. Some objects used as tools in the painting process are also investigated and explain textures seen in paint in his works. Samples of selected materials from the studio are analysed to identify the components of paints (pigments, extenders, and binders) used by Bacon. This investigation is part of a wider project examining his materials and techniques. The analytical information obtained here from the studio helps to clarify the statements made by Bacon in interviews regarding his use of materials and is proving useful in the identification of materials in his paintings, in order to help with the conservation and authentication of his works.  相似文献   

14.
《文物保护研究》2012,57(1):14-27
ABSTRACT

Zinc (carboxylate) soaps, formed by reactions between zinc oxide (ZnO) and fatty acids in a drying oil, are known to cause deterioration in the paint layers of modern and contemporary oil paintings. This study investigates zinc carboxylates that developed in an oil painting test panel designed to mimic the aging and degradation encountered in actual works of art. Following accelerated and natural aging, protrusions were noted on the surface of the test panel. A large protrusion with erupted gel features was extracted from the test panel, mounted in top view, and then cut to reveal the sample's cross section. The gel features, which resulted from the unreacted oil binder's separation from the paint matrix, facilitated zinc carboxylate formation. Using reflectance µ-FTIR and SEM-EDX analysis, the morphologies and spatial distributions of zinc carboxylates within the gel regions of the protrusion were studied. A concentration gradient of zinc within the gel material was observed in the cross-sectional view, indicating patterns of zinc carboxylate formation and migration.  相似文献   

15.
《文物保护研究》2013,58(3):231-249
Abstract

This paper presents a comparative investigation of recovery procedures for the analysis of natural organic colorants, encompassing ten major natural organic dye chemical classes, several sample types (silk, wool, cotton, pigment, paint), prepared from the extracts of twelve biological sources, and nine different recovery protocols. These protocols are based on the traditional harsh hydrochloric acid method; on mild hydrolysis methods involving formic, oxalic or hydrofluoric acid; and on methods consecutively employing mild and harsh hydrolysis on the same sample. An evaluation system was developed by classifying analytical results in an upper, middle or lower grade with reference to the best result obtained. This classification was used to calculate scores for each hydrolysis method and for either textile (silk and wool or cotton) or pigment/paint. The best overall hydrolysis method for textile samples was a combination of mild oxalic acid with traditional hydrochloric acid hydrolysis. The best overall hydrolysis method for pigment/paint was a combination of a newly modified mild hydrofluoric acid treatment with traditional hydrochloric acid hydrolysis. The application of these methods to historical samples will not necessarily give the optimal result achievable for every biological source, but will definitely reduce the risk of missing essential information for the elucidation of ancient technology in a geographical and historical context. The reduced level of risk will avoid repetitive sampling and reduce the level of invasiveness, hence taking into account good conservation policies. The potential of these selected methods is illustrated with the analysis of some historical Chinese textile and paint samples.  相似文献   

16.
《文物保护研究》2013,58(3):199-210
Abstract

Descente des vaches (1836) by Théodore Rousseau in the Mesdag Collection in The Hague is barely readable and its paint layers are in poor condition. The surface of the painting is strongly deformed and cracked, the whole painting has darkened and especially the greens have lost all or most of their colour resulting in brown passages. Large passages of the painting that were painted with multiple thick and medium-rich layers have darkened dramatically. This paper proposes that the degradation of Emerald green (Cu(C2H3O2)2·3Cu(AsO2)2, copperacetoarsenite) – the main green pigment used in this painting – is a significant factor in the cause of the darkening. Electron backscatter images reveal that the Emerald green particles are shown different degrees of degradation: from partially to completely disintegrated. Elemental maps show that arsenic is distributed throughout the paint cross section, with relatively higher concentrations around iron- and aluminium-containing particles, and in the varnish layer. Imaging-Fourier-transform infrared microscopy detects copper soaps in the degraded Emerald green-containing layers. Analytical data from four paint cross sections strongly suggest that Emerald green reacts with free fatty acids derived from the binding medium forming copper soaps and mobile arsenic-based species. Chemical laboratory experiments fully support this hypothesis. Emerald green and palmitic acid in chloroform form copper palmitate and arsenic trioxide (arsenolite, cubic) under room temperature and normal light conditions. The degradation of Emerald green particles in Descente des vaches has resulted in a loss of light-reflecting surfaces and in newly formed compounds in the paint, both contribute to the colour change from green to brown.  相似文献   

17.
Recent restoration of The Rest on the Flight into Egypt by Giovanni Francesco Caroto, from the Louvre collections, included a technical examination of the Virgin's blue robe that aimed to characterize the original materials and later additions. The painting was examined using light microscopy and ultraviolet and infrared imaging, and one cross section was taken. None of these methods showed a clear distinction between the layers that were artist applied or modifications made by another hand. To gain information about the paint stratigraphy without taking additional samples, non-invasive confocal X-ray fluorescence (CXRF) analysis was carried out to examine several areas of the Virgin's robe. Using this technique, it was possible to identify the pigments and order of application of paint by the artist. All the pigments identified were considered to be artist applied, and on this basis no further cleaning was carried out and conservation proceeded with retouching of minor areas of loss or damage. This study highlights the advantages of CXRF analysis for the technical study of paintings, used in combination with classical methods for making informed conservation treatment decisions.  相似文献   

18.
《文物保护研究》2013,58(4):139-149
Abstract

The study of the structure and materials of ancient works of art has been much intensified with the development and use of improved analytical techniques. It was considered desirable to apply an X-ray fluorescence technique which could scan polished cross-sections of paint materials embedded in plastic. Layer thicknesses of 20–50 μ were successfully surveyed with an X-ray macroprobe attached to a fine-focus vacuum X-ray spectrograph. Elements above atomic number 16 in areas of 50 μ diameter were successfully detected and precisely located in the cross-section. The method has been applied particularly to the study of the technique of Rembrandt and Lievens paintings.  相似文献   

19.
ABSTRACT

Twentieth century paints often contain titanium dioxide and zinc oxide based white pigments that can range from photostable to highly photocatalytic. Photocatalytic pigments can cause the degradation of paint upon UV exposure, whereas photostable pigments may be benign or can protect paintings from degradation. Hence, knowing whether or not a pigment is photocatalytic is of high importance for risk assessment and the subsequent decision making process concerning storage and exposure conditions of objects. Here we present a proof of principle, focused on titanium white paints, for an easy-to-use and low-tech application of a commercial photocatalytic activity indicator ink (PAII) on embedded paint samples or cross sections. This test determines, qualitatively, if a photocatalytic pigment is present in a white paint sample. The PAII paint sample staining application shows an obvious color change, within five minutes of UV irradiation, for paint samples containing photocatalytic pigments. A microscope with a camera and a UV source are the only necessary equipment for the application of this method. A quantitative image processing protocol is also proposed as an extension of the staining method by applying open source software analysis to measure the color change using photographs. The test was evaluated on reference paints with well-characterized pigments and applied on samples from modern paintings by Piet Mondriaan, Robert Ryman, and Lucebert, indicating the presence of harmful photocatalytic pigments in these cases. The novel application of a commercial ink on paint samples offers a simple test, not just for assessment of photocatalytic activity of titanium white pigments, but which may in future be applied for the detection of photoactive forms of zinc white and other potentially harmful semiconductor pigments in art objects.  相似文献   

20.
The identification of painting techniques is an important aspect of any research related to historical, artistic, and conservation issues in the field of wall paintings conservation. There are a variety of different methodological approaches that can be used to identify wall painting techniques. In this study, the application of optical (PLM) and electron (SEM-EDX) microscopy was explored as they are complementary analytical techniques commonly used for micro-stratigraphic analysis of painted surfaces. Five replicas were prepared according to the technical procedures reported in medieval historical treatises, and the pigment was applied at different time intervals in order to monitor the modifications at the interface between the ground and pictorial layer. The comparison of data from the replicas with samples from Romanesque wall paintings in churches in Southern Switzerland and Northern Lombardy (Italy) allowed for an evaluation of the reliability of the proposed methodology and for the interpretation of the painting techniques.  相似文献   

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