When paintings are examined by spectroscopic techniques, building a robust database is of major i... more When paintings are examined by spectroscopic techniques, building a robust database is of major importance, in order to compare the analyses with reliable references and to correctly understand the results. The database, which is usually homemade, should include carefully chosen commercial pigments, which should be as pure as possible and should correspond to the expected formula or composition of the historical pigments. Unfortunately, sometimes no correspondence between the names of the pigments used by companies and the actual composition of some of the colors is ascertained. In some cases, the composition is in fact made up of different chemical compounds; in others the presence of extenders is revealed, for example gypsum and calcite. In this paper some cases studies are discussed, regarding commercial pigments analysed by infrared spectroscopy, thermal analysis, X-ray diffraction and X-ray fluorescence. The results highlighted the importance of checking the purity of commercial pigments and excluding any extraneous compounds while interpreting the results of analytical survey of paintings.
HAL (Le Centre pour la Communication Scientifique Directe), 2019
When paintings are examined by spectroscopic techniques, building a robust database is of major i... more When paintings are examined by spectroscopic techniques, building a robust database is of major importance, in order to compare the analyses with reliable references and to correctly understand the results. The database, which is usually homemade, should include carefully chosen commercial pigments, which should be as pure as possible and should correspond to the expected formula or composition of the historical pigments. Unfortunately, sometimes no correspondence between the names of the pigments used by companies and the actual composition of some of the colors is ascertained. In some cases, the composition is in fact made up of different chemical compounds; in others the presence of extenders is revealed, for example gypsum and calcite. In this paper some cases studies are discussed, regarding commercial pigments analysed by infrared spectroscopy, thermal analysis, X-ray diffraction and X-ray fluorescence. The results highlighted the importance of checking the purity of commercial pigments and excluding any extraneous compounds while interpreting the results of analytical survey of paintings.
This paper presents the limitations and potential of ATR-FTIR spectroscopy applied to the study o... more This paper presents the limitations and potential of ATR-FTIR spectroscopy applied to the study of cellulosic textile collections. The technique helps to differentiate natural fibres according to the content of lignin, pectin, hemicellulose, and wax, although some problematic issues should be considered. The spectral differences derived from the environmental humidity uptake and the plant composition are reviewed and discussed in the light of new experimental data. Diagnostic bands are proposed that can discriminate between different fibres from different plants. The contribution of ageing is also considered, demonstrating that sometimes aged fibres cannot be reliably recognised. In contrast, the potential of ATR-FTIR spectroscopy to discriminate between natural and modified fibres is discussed and proven. The best results were obtained when microinvasive ATR-FTIR spectroscopy was coupled with SEM observations. The proposed protocol was tested on microsamples of various cellulosic m...
In this work, the "hi-tech" complex biocleaning and restoration of the 14th-century fresco Triump... more In this work, the "hi-tech" complex biocleaning and restoration of the 14th-century fresco Triumph of Death (5.6x15.0 m) at the Camposanto Monumental Cemetery (Pisa, Italy) is reported. Since 2000, the restoration based on the biological cleaning of noble medieval frescoes, has been successfully utilized in this site. Methods and Results: The novelty of this study is the 2-steps biocleaning process using Pseudomonas stutzeri A29 viable cells, previously applied for recovering other valuable frescoes. In this case, after the fresco detachment from the asbestos-cement support (eternity), both the animal glue and the residues of calcium caseinate were biologically removed respectively from the front and from the back of the fresco in 3 hours as indicated by GC-MS and PY/GC-MS analyses. The data obtained during the monitoring of the bio-restoration process confirmed that the adopted procedure does not leave residual cells on the fresco surfaces as showed by plate count method, ATP determination and also SEM observation. In addition, to avoid the risk of condensation phenomena after the relocation of the restored fresco sections onto the original walls, the use of a new support has been set up together with the design of a control system that allows a continuous monitoring of environmental parameters for prevention and conservation purposes.
This study is part of a comprehensive investigation that was performed in regard to a case of alt... more This study is part of a comprehensive investigation that was performed in regard to a case of alterations on a carbographic ribbon used in a typewriter that was found and seized by inner security operations of the Arma dei Carabinieri, Italy. Thirty-six coded scripts possessing potentially and criminally liable content were present on the tape; however, only the 6th and 7th scripts exhibited alterations of an uncertain nature. The study included sampling that was performed under sterile conditions of a large surface area of carbographic ribbons. A protocol based on physico-chemical, microbiological, and biomolecular tools was established. Preliminary results revealed the presence of fungal contamination that was primarily located on the inner surface of the 6th and 7th scripts on the black carbographic ribbon. One fungal strain was isolated and identified by universal ITS-PCR primer and rDNA sequencing as Alternaria infectoria strain NIS4. Fungal growth was monitored for 3 weeks in ...
To correctly manage a collection of historical silks, it is important to detect if the yarn has b... more To correctly manage a collection of historical silks, it is important to detect if the yarn has been originally subjected to degumming. This process is generally applied to eliminate sericin; the obtained fiber is named soft silk, in contrast with hard silk which is unprocessed. The distinction between hard and soft silk gives both historical information and useful indications for informed conservation. With this aim, 32 samples of silk textiles from traditional Japanese samurai armors (15th–20th century) were characterized in a non-invasive way. ATR-FTIR spectroscopy has been previously used to detect hard silk, but data interpretation is challenging. To overcome this difficulty, an innovative analytical protocol based on external reflection FTIR (ER-FTIR) spectroscopy was employed, coupled with spectral deconvolution and multivariate data analysis. The ER-FTIR technique is rapid, portable, and widely employed in the cultural heritage field, but rarely applied to the study of texti...
The ‘terre di rogo’ (pyre debris) are black-coloured layers resulting from the crematory pyres, p... more The ‘terre di rogo’ (pyre debris) are black-coloured layers resulting from the crematory pyres, placed inside graves within the ritual of secondary deposition and containing different materials, including cremation slags. The characterisation of the slags, until now rarely conducted by chemical techniques, can provide useful data to explain more precisely the protocol of the funeral ritual and to better understand the effects of fire during cremation for the accumulation of pyre debris. In this study, a fast screening method using ATR-mode infrared spectroscopy is proposed, which may highlight the need for further investigations with SEM and XRD. The protocol was tested on the black and irregularly shaped cremation slags from the pyre debris of two Iron Age cremation necropolises in Padua (northern Italy). The results of the analysis identified several types of cremation slags within each individual pyre ground and the presence of bone fragments exposed to different intensities of c...
The reproduction of natural stone using different kinds of mortars has always been an important c... more The reproduction of natural stone using different kinds of mortars has always been an important character of the architecture of Lombardy (Italy). Many examples of artificial stone, made of a coating of lime mortar on stone or brick structures, are available from Roman times. At the turn of the 20th century, a new kind of material, based on Portland cement and crushed stone, made possible a quite perfect reproduction of different kinds of stone and the making of complicated decorative elements. The raw materials employed to reproduce white marble and other stones used in Lombard architecture were investigated starting from the 'Fontana di Camerlata' (Como, 1936-62)
Aims: In this study the results of the use of a new agar-gauze biogel system activated by viable ... more Aims: In this study the results of the use of a new agar-gauze biogel system activated by viable bacterial cells applied on altered wall-paintings are reported. Methods and Results: Biocleaning using agar biogel and agar-gauze biogel systems was performed onsite by direct application onto altered wall-painting artwork surfaces (25-1,000 cm2). The treatments were performed for the restoration of two original Italian sites: i) at the Vatican Museums, Cristo che salva Pietro dalle acque - La Navicella wall-painting by Giovanni Lanfranco (1627-1628) and ii) at Pisa Cathedral Cupola, Incarnato wall-painting by Orazio Riminaldi (1593-1630) and his brother (Girolamo Riminaldi). The novelty of this study is the use of Pseudomonas stutzeri A29 viable cells using an advanced agar-gauze biogel system and that the bioapplications required short contact-times of between 3-12 hours. The ancient artworks were altered by lipid and protein residues from past restoration as confirmed by the Py-GC/MS ...
When paintings are examined by spectroscopic techniques, building a robust database is of major i... more When paintings are examined by spectroscopic techniques, building a robust database is of major importance, in order to compare the analyses with reliable references and to correctly understand the results. The database, which is usually homemade, should include carefully chosen commercial pigments, which should be as pure as possible and should correspond to the expected formula or composition of the historical pigments. Unfortunately, sometimes no correspondence between the names of the pigments used by companies and the actual composition of some of the colors is ascertained. In some cases, the composition is in fact made up of different chemical compounds; in others the presence of extenders is revealed, for example gypsum and calcite. In this paper some cases studies are discussed, regarding commercial pigments analysed by infrared spectroscopy, thermal analysis, X-ray diffraction and X-ray fluorescence. The results highlighted the importance of checking the purity of commercia...
Abstract The paper presents the analytical campaign carried out on the Baroque stucco decorations... more Abstract The paper presents the analytical campaign carried out on the Baroque stucco decorations by Italian artists known as Artists of the Lakes. Forty samples (from moldings, background, sculpture bas- and high- reliefs) from the churches of S. Lorenzo in Laino, S. Maria dei Ghirli in Campione d’Italia and S. Maria Assunta in Puria (Como, Italy) were analysed by chemical and mineralogical techniques and the data were discussed with a multi-disciplinary approach with art historians, in order to enlighten and compare the artistic techniques. Binders, aggregates, pigments and organic fractions were determined using optical microscopy, scanning electron microscopy with EDS microprobe, X-ray powder diffraction, Raman and Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry. The substrate is constituted by a mixture of magnesian lime, silicatic and/or carbonatic aggregate. Layers sequence varies from the simple pattern of S. Maria dei Ghirli, (1 or 2 layers), to the complexity of S. Lorenzo where up to 9 layers above the substrate were observed. Pigment particles were identified as ochres and as green earth in a single case. Three different gilding techniques are described, as the gold leaf is applied over a chrome yellow ground (a missione), over a layer composed by ochre and lead white or over a brass leaf. In some cases organic materials were recognized: oil in gilding preparations and egg mixed with ochre pigments. A carbon black based pigment was identified by Raman spectroscopy in some decorative motifs. The sequence and composition of the finishing layers, the accumulation of particulate matter and the use of gypsum on purpose depending on the decorations typology, enlightened the artist skills, showing how different needs and timing influenced the commissions in the buildings.
The paper describes the analysis of a particular kind of plaster from the walls of the Roman Sanc... more The paper describes the analysis of a particular kind of plaster from the walls of the Roman Sanctuary (first half of the 1 st century BCE) in the centre of Brixia (now Brescia, Italy), which is an outstanding example of Roman Republican architecture. The walls were plastered and painted with different patterns, imitating marble panels and curtains. Optical microscopy on thin sections, X-ray diffraction, and infrared spectroscopy were performed on several samples of the plaster in order to reveal the execution technique. The palette consisted of glauconite, celadonite, Egyptian blue, and red and yellow ochres. In some cases, an organic compound, possibly a lipidic compound, was present in the external paint layer, as a surface treatment. The plaster contains two superimposed coats: the render coat with lime binder and sandy aggregate; the finish coat with a clay fraction (illite, chlorite, kaolinite), together with calcite from slaked lime and grains of quartz, silicate and carbonate rocks. Although Vitrivius' De Architectura reported the use of creta (clay) as daub smeared on reed vaults, the Sanctuary of Brixia represents the first documented use in Roman buildings in a painted plaster laying on a stone masonry wall.
When paintings are examined by spectroscopic techniques, building a robust database is of major i... more When paintings are examined by spectroscopic techniques, building a robust database is of major importance, in order to compare the analyses with reliable references and to correctly understand the results. The database, which is usually homemade, should include carefully chosen commercial pigments, which should be as pure as possible and should correspond to the expected formula or composition of the historical pigments. Unfortunately, sometimes no correspondence between the names of the pigments used by companies and the actual composition of some of the colors is ascertained. In some cases, the composition is in fact made up of different chemical compounds; in others the presence of extenders is revealed, for example gypsum and calcite. In this paper some cases studies are discussed, regarding commercial pigments analysed by infrared spectroscopy, thermal analysis, X-ray diffraction and X-ray fluorescence. The results highlighted the importance of checking the purity of commercial pigments and excluding any extraneous compounds while interpreting the results of analytical survey of paintings.
HAL (Le Centre pour la Communication Scientifique Directe), 2019
When paintings are examined by spectroscopic techniques, building a robust database is of major i... more When paintings are examined by spectroscopic techniques, building a robust database is of major importance, in order to compare the analyses with reliable references and to correctly understand the results. The database, which is usually homemade, should include carefully chosen commercial pigments, which should be as pure as possible and should correspond to the expected formula or composition of the historical pigments. Unfortunately, sometimes no correspondence between the names of the pigments used by companies and the actual composition of some of the colors is ascertained. In some cases, the composition is in fact made up of different chemical compounds; in others the presence of extenders is revealed, for example gypsum and calcite. In this paper some cases studies are discussed, regarding commercial pigments analysed by infrared spectroscopy, thermal analysis, X-ray diffraction and X-ray fluorescence. The results highlighted the importance of checking the purity of commercial pigments and excluding any extraneous compounds while interpreting the results of analytical survey of paintings.
This paper presents the limitations and potential of ATR-FTIR spectroscopy applied to the study o... more This paper presents the limitations and potential of ATR-FTIR spectroscopy applied to the study of cellulosic textile collections. The technique helps to differentiate natural fibres according to the content of lignin, pectin, hemicellulose, and wax, although some problematic issues should be considered. The spectral differences derived from the environmental humidity uptake and the plant composition are reviewed and discussed in the light of new experimental data. Diagnostic bands are proposed that can discriminate between different fibres from different plants. The contribution of ageing is also considered, demonstrating that sometimes aged fibres cannot be reliably recognised. In contrast, the potential of ATR-FTIR spectroscopy to discriminate between natural and modified fibres is discussed and proven. The best results were obtained when microinvasive ATR-FTIR spectroscopy was coupled with SEM observations. The proposed protocol was tested on microsamples of various cellulosic m...
In this work, the "hi-tech" complex biocleaning and restoration of the 14th-century fresco Triump... more In this work, the "hi-tech" complex biocleaning and restoration of the 14th-century fresco Triumph of Death (5.6x15.0 m) at the Camposanto Monumental Cemetery (Pisa, Italy) is reported. Since 2000, the restoration based on the biological cleaning of noble medieval frescoes, has been successfully utilized in this site. Methods and Results: The novelty of this study is the 2-steps biocleaning process using Pseudomonas stutzeri A29 viable cells, previously applied for recovering other valuable frescoes. In this case, after the fresco detachment from the asbestos-cement support (eternity), both the animal glue and the residues of calcium caseinate were biologically removed respectively from the front and from the back of the fresco in 3 hours as indicated by GC-MS and PY/GC-MS analyses. The data obtained during the monitoring of the bio-restoration process confirmed that the adopted procedure does not leave residual cells on the fresco surfaces as showed by plate count method, ATP determination and also SEM observation. In addition, to avoid the risk of condensation phenomena after the relocation of the restored fresco sections onto the original walls, the use of a new support has been set up together with the design of a control system that allows a continuous monitoring of environmental parameters for prevention and conservation purposes.
This study is part of a comprehensive investigation that was performed in regard to a case of alt... more This study is part of a comprehensive investigation that was performed in regard to a case of alterations on a carbographic ribbon used in a typewriter that was found and seized by inner security operations of the Arma dei Carabinieri, Italy. Thirty-six coded scripts possessing potentially and criminally liable content were present on the tape; however, only the 6th and 7th scripts exhibited alterations of an uncertain nature. The study included sampling that was performed under sterile conditions of a large surface area of carbographic ribbons. A protocol based on physico-chemical, microbiological, and biomolecular tools was established. Preliminary results revealed the presence of fungal contamination that was primarily located on the inner surface of the 6th and 7th scripts on the black carbographic ribbon. One fungal strain was isolated and identified by universal ITS-PCR primer and rDNA sequencing as Alternaria infectoria strain NIS4. Fungal growth was monitored for 3 weeks in ...
To correctly manage a collection of historical silks, it is important to detect if the yarn has b... more To correctly manage a collection of historical silks, it is important to detect if the yarn has been originally subjected to degumming. This process is generally applied to eliminate sericin; the obtained fiber is named soft silk, in contrast with hard silk which is unprocessed. The distinction between hard and soft silk gives both historical information and useful indications for informed conservation. With this aim, 32 samples of silk textiles from traditional Japanese samurai armors (15th–20th century) were characterized in a non-invasive way. ATR-FTIR spectroscopy has been previously used to detect hard silk, but data interpretation is challenging. To overcome this difficulty, an innovative analytical protocol based on external reflection FTIR (ER-FTIR) spectroscopy was employed, coupled with spectral deconvolution and multivariate data analysis. The ER-FTIR technique is rapid, portable, and widely employed in the cultural heritage field, but rarely applied to the study of texti...
The ‘terre di rogo’ (pyre debris) are black-coloured layers resulting from the crematory pyres, p... more The ‘terre di rogo’ (pyre debris) are black-coloured layers resulting from the crematory pyres, placed inside graves within the ritual of secondary deposition and containing different materials, including cremation slags. The characterisation of the slags, until now rarely conducted by chemical techniques, can provide useful data to explain more precisely the protocol of the funeral ritual and to better understand the effects of fire during cremation for the accumulation of pyre debris. In this study, a fast screening method using ATR-mode infrared spectroscopy is proposed, which may highlight the need for further investigations with SEM and XRD. The protocol was tested on the black and irregularly shaped cremation slags from the pyre debris of two Iron Age cremation necropolises in Padua (northern Italy). The results of the analysis identified several types of cremation slags within each individual pyre ground and the presence of bone fragments exposed to different intensities of c...
The reproduction of natural stone using different kinds of mortars has always been an important c... more The reproduction of natural stone using different kinds of mortars has always been an important character of the architecture of Lombardy (Italy). Many examples of artificial stone, made of a coating of lime mortar on stone or brick structures, are available from Roman times. At the turn of the 20th century, a new kind of material, based on Portland cement and crushed stone, made possible a quite perfect reproduction of different kinds of stone and the making of complicated decorative elements. The raw materials employed to reproduce white marble and other stones used in Lombard architecture were investigated starting from the 'Fontana di Camerlata' (Como, 1936-62)
Aims: In this study the results of the use of a new agar-gauze biogel system activated by viable ... more Aims: In this study the results of the use of a new agar-gauze biogel system activated by viable bacterial cells applied on altered wall-paintings are reported. Methods and Results: Biocleaning using agar biogel and agar-gauze biogel systems was performed onsite by direct application onto altered wall-painting artwork surfaces (25-1,000 cm2). The treatments were performed for the restoration of two original Italian sites: i) at the Vatican Museums, Cristo che salva Pietro dalle acque - La Navicella wall-painting by Giovanni Lanfranco (1627-1628) and ii) at Pisa Cathedral Cupola, Incarnato wall-painting by Orazio Riminaldi (1593-1630) and his brother (Girolamo Riminaldi). The novelty of this study is the use of Pseudomonas stutzeri A29 viable cells using an advanced agar-gauze biogel system and that the bioapplications required short contact-times of between 3-12 hours. The ancient artworks were altered by lipid and protein residues from past restoration as confirmed by the Py-GC/MS ...
When paintings are examined by spectroscopic techniques, building a robust database is of major i... more When paintings are examined by spectroscopic techniques, building a robust database is of major importance, in order to compare the analyses with reliable references and to correctly understand the results. The database, which is usually homemade, should include carefully chosen commercial pigments, which should be as pure as possible and should correspond to the expected formula or composition of the historical pigments. Unfortunately, sometimes no correspondence between the names of the pigments used by companies and the actual composition of some of the colors is ascertained. In some cases, the composition is in fact made up of different chemical compounds; in others the presence of extenders is revealed, for example gypsum and calcite. In this paper some cases studies are discussed, regarding commercial pigments analysed by infrared spectroscopy, thermal analysis, X-ray diffraction and X-ray fluorescence. The results highlighted the importance of checking the purity of commercia...
Abstract The paper presents the analytical campaign carried out on the Baroque stucco decorations... more Abstract The paper presents the analytical campaign carried out on the Baroque stucco decorations by Italian artists known as Artists of the Lakes. Forty samples (from moldings, background, sculpture bas- and high- reliefs) from the churches of S. Lorenzo in Laino, S. Maria dei Ghirli in Campione d’Italia and S. Maria Assunta in Puria (Como, Italy) were analysed by chemical and mineralogical techniques and the data were discussed with a multi-disciplinary approach with art historians, in order to enlighten and compare the artistic techniques. Binders, aggregates, pigments and organic fractions were determined using optical microscopy, scanning electron microscopy with EDS microprobe, X-ray powder diffraction, Raman and Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry. The substrate is constituted by a mixture of magnesian lime, silicatic and/or carbonatic aggregate. Layers sequence varies from the simple pattern of S. Maria dei Ghirli, (1 or 2 layers), to the complexity of S. Lorenzo where up to 9 layers above the substrate were observed. Pigment particles were identified as ochres and as green earth in a single case. Three different gilding techniques are described, as the gold leaf is applied over a chrome yellow ground (a missione), over a layer composed by ochre and lead white or over a brass leaf. In some cases organic materials were recognized: oil in gilding preparations and egg mixed with ochre pigments. A carbon black based pigment was identified by Raman spectroscopy in some decorative motifs. The sequence and composition of the finishing layers, the accumulation of particulate matter and the use of gypsum on purpose depending on the decorations typology, enlightened the artist skills, showing how different needs and timing influenced the commissions in the buildings.
The paper describes the analysis of a particular kind of plaster from the walls of the Roman Sanc... more The paper describes the analysis of a particular kind of plaster from the walls of the Roman Sanctuary (first half of the 1 st century BCE) in the centre of Brixia (now Brescia, Italy), which is an outstanding example of Roman Republican architecture. The walls were plastered and painted with different patterns, imitating marble panels and curtains. Optical microscopy on thin sections, X-ray diffraction, and infrared spectroscopy were performed on several samples of the plaster in order to reveal the execution technique. The palette consisted of glauconite, celadonite, Egyptian blue, and red and yellow ochres. In some cases, an organic compound, possibly a lipidic compound, was present in the external paint layer, as a surface treatment. The plaster contains two superimposed coats: the render coat with lime binder and sandy aggregate; the finish coat with a clay fraction (illite, chlorite, kaolinite), together with calcite from slaked lime and grains of quartz, silicate and carbonate rocks. Although Vitrivius' De Architectura reported the use of creta (clay) as daub smeared on reed vaults, the Sanctuary of Brixia represents the first documented use in Roman buildings in a painted plaster laying on a stone masonry wall.
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