Costanza Miliani

Italian National Research Council | CNR · Institute of Heritage Science

This paper presents firm evidence for the chemical alteration of chrome yellow pigments in Van Gogh's Sunflowers (Van Gogh Museum, Amsterdam). Noninvasive in situ spectroscopic analysis at several spots on the painting, combined with synchrotron-radiation-based X-ray investigations of two microsamples, revealed the presence of different types of ch...

Environmental factors, such as light, humidity and temperature are triggering agents for the alteration of organic and/or inorganic constituents of oil paintings. The oxidation of the organic material is favored by increasing of relative humidity and temperature, whereas processes involving changes of the oxidation states of a number of inorganic p...

Cultural detective work: Remote hyperspectral imaging in the mid-infrared region enables the identification and localization of the painting materials used by artists (see brightness temperature difference image overlayed with the corresponding portion of the painting Sestante 10 by Alberto Burri and IR reflection spectra for this area). The result...

The fugitive nature of the colorants obtained from sappanwood (Caesalpinia sappan L.) or the South American species commonly known as ‘brazilwoods’ (including other Caesalpinia species and Paubrasilia echinata (Lam.)) makes the identification of brazilwood dyes and pigments in historic artefacts analytically challenging. This difficulty has been so...

In this review, the main technological processes involved in the production of color in glasses, ceramics and pigments are reported. Iron (as oxides or dispersed ion) is the main responsible of the color in archeological and historical ceramics and glasses, but other d-metals can be also found (Cu, Ag, Co, Cr, Ni) as nano-particles or dispersed ion...

The present research exploits the strengths of external reflection FT-IR spectroscopy to non-invasively study heritage plastic objects through inspection, for the first time, of the wide spectral range including the near- and mid-IR (12500-350cm⁻¹). Unlike most of previous works on historical plastic objects, reflection-mode spectra were not correc...

Among the artists’ materials of the nineteenth century, pastel crayons merit scientific interest since their early commercial formulations are mostly unknown and, until now, have been considerably less studied with respect to other contemporary painting materials. In this framework, research herein reports the results of a comprehensive multi-analy...

In Heritage Science, the evaluation of stone consolidation treatments by investigating the nature of in situ newly formed products and their penetration depth within the consolidated matrix is a grand challenge. A number of analytical methods have been proposed, but, currently, most of them are not able to supply a full overview of the spatial, str...

We present the results of a diagnostic campaign on three of Giuseppe Capogrossi’s abstract paintings from the 1950s and 1960s, conserved at the National Gallery of Modern and Contemporary Art in Rome. Non-invasive investigations by reflection FT-IR spectroscopy were carried out, followed by micro-destructive laboratory analyses using Py-GC-MS, and...

The electronic and vibrational properties of red lead pigment, the mixed valence lead oxide compound Pb3O4, known as minium, have been studied by means of first principle calculations based on Density Functional Theory (DFT) and Fourier Transform–Infra Red (FT-IR) and Raman spectroscopies. The aim of the present investigation is to validate an inte...

The aim of the present chapter is to evaluate the introduction of oil-modified alkyd resins in the painting practice of Jackson Pollock. Using a non-invasive approach based on FT-IR reflection spectroscopy measurements, eleven works by the artist dated from 1942 to 1947 have been examined at the Peggy Guggenheim Collection (PGC, Solomon R. Guggenhe...

The article illustrates the MOLAB research project devoted to the non-invasive investigation of pre-Hispanic and colonial Mesoamerican manuscripts. In the present paper, we provide a description of the project and its aims, listing the artworks so far investigated and describing analytical techniques we employed. A presentation of the data obtained...

The degradation of cadmium sulfide (CdS)–based oil paints is a phenomenon potentially threatening the iconic painting The Scream (ca. 1910) by Edvard Munch (Munch Museum, Oslo) that is still poorly understood. Here, we provide evidence for the presence of cadmium sulfate and sulfites as alteration products of the original CdS-based paint and explor...

The control of surface cleaning procedures of paintings is difficult and residues of cleaning materials can remain on the surface as potential risk factors for the integrity of the original paint layers. Therefore, the development of a suitable analytical strategy for in situ detection of cleaning residues directly on the painting surface is essent...

Geranium lake is an eosin-derived organic pigment highly employed by Van Gogh and his contemporaries. Its elusive behavior, observed in a large number of post-impressionism masterpieces, is of current concern for both conservators and heritage scientists. Herein, the lightfastness of Geranium lake within oil matrix has been investigated by means UV...

This study is aimed at clarifying the causes of lead white darkening by studying the behaviour of its two components: cerussite and hydrocerussite. Their degradation processes have been investigated by micro‐Raman spectroscopy both in an alkaline environment generated from a fresco conditions and in the presence of NaClO as an external oxidizing ag...

In this study a multi-analytical approach has been performed to characterise the constitutive materials of an ancient painted barkcloth or Tapa. Originating from Wallis Island, Polynesia, this cloth likely served utilitarian or ceremonial purposes and is part of the Felice Junck collection at the Pigorini, Muciv museum of Rome. During a recent cons...

The relevance of FT-IR spectroscopy in heritage science has experienced a constant grow in the last two decades owing to analytical peculiarities that make it an extremely useful tool to answer the questions posed by the study and conservation of art-historical and archaeological materials. High versatility, sensitivity and molecular specificity ar...

The identification of natural dyes in ancient textiles is a longstanding challenge for scientists; yet, the effort honours the skill and knowledge of master dyers by retracing traditional dyeing methods and assisting in conserving historical treasures for future generations. Here, the main constituents of selected native Japanese extracts from the...

Vincent van Gogh used fugitive red lake pigments that have faded in some paintings. Mapping their distribution is key to understanding how his paintings have changed with time. While red lake pigments can be identified from microsamples, in situ identification and mapping remains a challenge. This paper explores the ability of molecular fluorescenc...

Vincent van Gogh used fugitive red lake pigments that have faded in some paintings. Mapping their distribution is key to understanding how his paintings have changed with time. While red lake pigments can be identified from microsamples, in situ identification and mapping remains a challenge. This paper explores the ability of molecular fluorescenc...

Abstract Maya blue is a hybrid pigment where an organic component, indigo, is incorporated in a porous clay. Despite its widespread use in the Mesoamerican artistic production and numerous studies devoted to understand the type of interactions between indigo and the host framework, its technology has not been completely unravelled yet. In this stud...

The performance of non-invasive chemical analyses on various pre-Hispanic Mesoamerican codices to chemically characterize their painting materials has recently opened new avenues into research on the ancient Mesoamerican book painting tradition. In this chapter, a comparative effort is undertaken in order to shed light on the technological relation...

During solvent cleaning of a painted surface, the control of solvent diffusion into the painting matrix is a primary concern for conservators. In this work, a comparative systematic study of solvent ingress and of the ensuing swelling phenomenon in paint films due to cleaning treatments was tackled using single-sided NMR. Specifically, the effects...

Calcium acetoacetate, Ca(OAcAc)2, was exposed 7, 30 and 365 days to different values of relative humidity(33%, 48%, 75% and 96%) at 40 °C in order to study its transformation to CaCO3. The resulting Ca(OAcAc)2 decomposition and the time dependence of the phase transformations were monitored and critically evaluated by Fourier transform infrared spe...

The relevance of FT-IR spectroscopy in heritage science has experienced a constant grow in the last two decades owing to analytical peculiarities that make it an extremely useful tool to answer the questions posed by the study and conservation of art-historical and archaeological materials. High versatility, sensitivity and molecular specificity ar...

Nowadays the use of laser technology as a highly precise tool for the cleaning of paintings is gaining ground. The development of a non-invasive analytical protocol aimed at thorough assessment of the treated surfaces and real time monitoring of the laser cleaning action is thus becoming imperative. This ensures that no side effects (e.g. discolora...

This work presents the implementation of Visible Hyperspectral Imaging for the in-situ analysis of glass chromophores in two glass windows from the Casa-Museu Dr. Anastácio Gonçalves (Lisbon, Portugal). The measurements were taken inside the building using natural sunlight as the illumination source. In addition, advantages and disadvantages of the...

The darkening due to chemical alteration of chrome yellows (PbCrO 4 /PbCr 1-x S x O 4 ) is a phenomenon threatening a large number of 19th-20th century paintings, including the Amsterdam Sunflowers by Vincent van Gogh. Our earlier studies have proven that the alteration is due to a Cr(VI) a' Cr(III) reduction with Cr(V)-species that are formed as l...

This chapter discusses the potential of reflection mid-FTIR spectroscopy for in situ identification and localization of metal oxalates and carboxylates in paintings. The infrared reflection profiles of the most common metal oxalates and carboxylates are discussed through the direct comparison with reference powders and model samples demonstrating t...

The bleaching of cadmium yellows is a problem that affect paintings by famous artists, such as, Matisse, Van Gogh, and Munch. Synchrotron radiation‐based X‐ray techniques, UV‐Vis, and FTIR spectroscopies unveils the key role played by moisture and light in the discoloration process of cadmium yellow oil paints. The image shows a simplified version...

With the aim of studying the process of blackening of lead white in mural painting, a set of samples from the Cimabue's paintings at the Assisi Cathedral have been studied by Raman and XRD methods, complemented with related techniques (i.e. reflection FTIR, XRF, SEM-EDS). The investigation highlighted that a complete oxidation of lead white to lead...

Cadmium yellows (CdYs) refer to a family of cadmium sulfide pigments which have been widely used by artists since the late 19th c. Despite being considered stable, they are suffering from discoloration in iconic paintings, such as Joy of Life by Matisse, Flowers in a blue vase by Van Gogh and the Scream by Munch, most likely due to the formation of...

The absorption of light gives a pigment its colour and its raison d'être, but it also creates excited states, new molecules with an energy excess that can be dissipated through degradation pathways. Photodegradation processes provoke long‐term, cumulative and irreversible colour changes (fading, darkening, blanching) of which the prediction and pre...

In this work the formulation of 20 Johann Faber felt-tip pens commercialized in the 1960s and belonging to and used by the architect and designer Lina Bo Bardi have been investigated by an integrated analytical methodology. Minimally destructive vibrational spectroscopic methods permitted a qualitative interpretation of constituents which could be...

Here, we report on the analytical findings and their cultural implications of a multidisciplinary study of the pre-Columbian Codex Fejérváry-Mayer. Today conserved at the World Museum in Liverpool, it is one of the finest Mesoamerican codices among the few extant. Thanks to the exploitation of non-invasive analytical methodologies accessible throug...

The absorption of light gives a pigment its colour and its raison d'être, but it also creates excited states, new molecules with an energy excess that can be dissipated through degradation pathways. Photodegradation processes provoke long‐term, cumulative and irreversible colour changes (fading, darkening, blanching) of which the prediction and pre...

The composition of the ancient wax-based painting technique known as encaustic has long been the subject of debate. Ancient sources provide few details of the technology, and modern understanding of the medium is restricted to theoretical interpretation and experimental observation. In this multi-analytical collaborative study, a number of analytic...

The prized ancient dyestuff, Tyrian purple, has been extensively and widely studied by multiple spectroscopic and chromatographic methods alike. In this paper, an extraction method adopted by liquid chromatography by using N,N-dimethylformamide is proposed as a sample pre-treatment for the characterization of minor reference brominated and unsubsti...

A new analytical approach, based on micro-transflection measurements from a diamond-coated metal sampling stick, is presented for the analysis of painting varnishes. Minimally invasive sampling is performed from the varnished surface using the stick, which is directly used as a transflection substrate for micro Fourier transform infrared (FTIR) mea...

CRONO is a new portable and easy reconfigurable macro X-ray fluorescence scanner based on the energy dispersive X-ray fluorescence technique, which has been specifically designed for in-situ, fast, and non-invasive elemental mapping of polychrome surfaces. The main components are fully integrated into the detection head which includes an X-ray tube...

The in situ non invasive methods have experienced a significant development in the last decade because they meet specific needs of analytical chemistry in the field of cultural heritage where artworks are rarely moved from their locations, sampling is rarely permitted, and analytes are a wide range of inorganic, organic and organometallic substance...

Motivated by the fugitive and undisclosed nature of eosin-derived pigments as used by Vincent van Gogh, this paper presents the syntheses of monometallic and historical bimetallic eosin-based lakes and structural elucidation by MS, ATR-FTIR and NMR. Specifically two monometallic (Al, Pb) and several bimetallic lakes (on varying Al and Pb constituen...

Protrusions, efflorescence, delamination and opacity decreasing are severe degradation phenomena affecting oil-paints with zinc oxide, one of the most common white pigments of the 20th century. Responsible of these dramatic alterations are the Zn-carboxylates (also known as Zn-soaps) originated by the interaction of the pigment and the fatty acids...

The introduction of synthetic dyes and pigments into commerce in the late 19th century was a stimulating time for experimental scientists in their laboratory formulations and for artists in their usage. Nowadays, the period of pioneering syntheses and employment of synthetic organic colouring materials is highly intriguing for scientific research a...

A complete non-invasive characterization by XRF, XRD, near-FTIR and UV–Vis reflectance spectroscopy has been performed on some commercially available violet pigments as well as on pure violet Co-salts also known to be used as pigments. The obtained results show that, after a preliminary elemental characterization, the studied pigments can be easily...