Surface Of Artwork Research Articles

High-resolution compound-specific mapping in works of art via data fusion of MA-XRPD with hyperspectral data (part 1: Method evaluation)

BackgroundHyperspectral imaging techniques have emerged as powerful tools for non-invasive investigation of artworks. This paper employs either reflectance imaging spectroscopy (RIS) or macroscopic X-ray fluorescence (MA-XRF) imaging in combination with macroscopic X-ray powder diffraction (MA-XRPD) for state-of-the-art chemical imaging of painted cultural heritage artefacts. While RIS can provide molecular information and MA-XRF can offer elemental distribution maps of paintings of high lateral resolution, the unique advantage of MA-XRPD lies in its ability to visualize the distributions of specific pigments and estimate in a quantitative manner the relative concentrations of the crystalline phases at the surface of artworks. However, MA-XRPD is more time-consuming and offers a lower lateral resolution than RIS and MA-XRF. ResultsThis study introduces a machine learning (ML) approach to obtain the distribution of specific compounds on the surface of artworks with a resolution that is comparable to that of RIS and MA-XRF data but with the compound specificity of MA-XRPD. The general aim is to expedite non-destructive artwork imaging analysis by fusing data from different imaging modalities via machine learning models. The effect of preprocessing techniques to enhance the predictive accuracy of the models is explored. The paper demonstrates the method's efficacy on a 16th-century illuminated manuscript, showcasing the feasibility of predicting compound-specific distribution maps. Three evaluation methods—visual examination of the predicted distribution, root mean square errors (RMSE), and feature permutation importance (FPI)—are employed to assess model performance. Fusing MA-XRF with MA-XRPD led to the best RMSE scores overall. However, fusing the RIS and MA-XRPD data blocks also yield very satisfactory and easily interpretable high-resolution compound maps. SignificanceWhile MA-XRPD allows for highly specific imaging of artworks, its time-consuming nature and limited resolution presents a bottleneck during non-invasive imaging of painted works of art. By integrating data from more time-efficient hyperspectral techniques such as MA-XRF and RIS, and employing machine learning, we expedite the process without compromising accuracy. The fusion process can also denoise the distribution maps, improving their readability for heritage professionals and art historical scholars.

Pickering Emulsion Gel Based on Funori Biopolymer and Halloysite Nanotubes: A New Sustainable Material for the Cleaning of Artwork Surfaces

Pickering Emulsion Gel Based on <i>Funori</i> Biopolymer and Halloysite Nanotubes: A New Sustainable Material for the Cleaning of Artwork Surfaces

Stealing from Phytotherapy—Heritage Conservation with Essential Oils: A Review, from Remedy to Sustainable Restoration Product

Essential oils represent a good alternative to chemical biocides as they have antiseptic, antibacterial and antifungal properties, inhibiting the formation and proliferation of biofilms which can occur on outdoor and indoor surfaces of ancient and modern artworks. In this review, we illustrate how their antimicrobial properties, known since antiquity in phytotherapy, have been studied and tested for conservation purposes since the 1970s. In vitro tests on a wide range of plant extracts and in situ applications of specific volatile compounds have shown selective antibacterial and antifungal properties after the individual action of pure components or as the synergic effects of pre-determined mixtures. The review emphasizes the broad spectrum of materials—organic and inorganic—that essential oils can be applied to as biocides and finally emphasizes how the demand for commercial solutions has rapidly grown in bioconservation. The review demonstrates how research on the subject has been powerfully boosted by the ecofriendly and harmless character of essential oil applications, which makes them one of the most sustainable options in heritage conservation nowadays. The review elucidates how research is developing novel solutions for the application of EO blends—like encapsulation and microemulsions—and their optimization in commercial products for heritage conservation.

Interferometric Quantification of the Impact of Relative Humidity Variations on Cultural Heritage

It has been shown that Relative Humidity (RH) provokes dimensional displacement detectable directly from surfaces using holographic interferometry. RH variations constitute a physical environmental load that drives organic materials to a constant equilibrium cycle. This paper is a small synopsis of the interferometric research direction and a data acquisition on the detection of the dimensional impact of relative humidity on cultural heritage objects. Since RH cycling is unavoidable, the interferometric data change depends on the object structure and RH cycle characteristics. Based on the fact that each artwork is by construction unique, and on the observation that the effects of an RH cycle on the structural condition of any artwork are also unique but the preventive conservation strategies require generalised approaches and not on a case-by-case study, being introduced is a novel, universal, preventive deterioration methodology: “deformation threshold value” (DTV). DTV is assignable to each distinct object in order to control routinely its structural condition and prevent damage. DTV is not assigned hypothetically based on any assumed/expected reactions but from a monitored calibration of the artwork in its environment. Each artwork in its hosted environment has its unique reaction. The reaction, though, is not steady but changes as the artwork changes. DTV can be acquired routinely and valued accordingly to seasonal RH change. Monitoring the seasonal RH and seasonal dimensional reaction has been shown to correspond to a standard DTV pattern whose deviations violate the expected seasonal reaction. Through the interferometric monitoring of surface, the distinct DTV acts as a safeguard for the artwork. In this synopsis, some results of the generation of DTVs are shown. Our future plan is for the DTV numbers to serve as data inputs for preventive models to formulate a distinct risk index representative of each artwork condition and to be used as remote risk warning to prevent its deterioration. Based on the DTV concept, methods and instruments for sequential data acquisition aim to present experimental data outputs as DTVs that identify transient shape changes prior to visible damage have been developed. In this research, the starting point was the interferometric quantification of the displacement of well-characterized fresh samples. The fresh samples are known in terms of density, cut, thickness, moisture content, structural condition and are submitted to RH simulation cycles. Shown here are three exemplary cases: usual, abrupt and smooth. The interferometric monitoring following the cycles of RH is a long-term duration of several weeks; measurements are performed directly from the surface, and relative displacement (RD) from temporal measurements of interference fringes provide the required output data to calculate the rate of displacement (RoD) of the surface. Measuring the impact of RH directly from the artwork surface allows the detection of the temporal diversity of structural reactions to the same RH cycle for distinct artworks. The monitoring system uses interferometric precision provided by digital holographic speckle-pattern interferometry (DHSPI) placed on a specially designed climate chamber DHSPI monitoring workstation.

Surface Displacement Measurements of Artworks: New Data Processing for Speckle Pattern Interferometry

Curators have developed preventive conservation strategies and usually try to control the temperature (T) and relative humidity (RH) variations in the museum rooms to stabilise the artworks. The control systems chosen by museums depend on the size and age of the building, the financial means and the strategies that can be adapted. However, there is a lack of methods that can monitor mechanical changes or chemical reactions of objects in real-time or regularly. It would therefore ideally be preferable to monitor each of them to alert them to preserve them. For this purpose, a non-destructive, non-contact, full-field technique, Digital Holographic Speckle Pattern Interferometry (DHSPI), has already been developed and allows direct tracking of changes on the surface of artworks. This technique is based on phase-shifting speckle interferometry and gives the deformation of the surface below the level of the micro-meter of the analysed object. In order to monitor the deformation continuously, a large number of images are acquired by DHSPI and have to be processed. The existing process consists of removing noise from the interferogram, unwrapping this image, and deriving and displaying a 2D or 3D deformation map. In order to improve the time and accuracy of processing the imaging data, a simpler and faster processing method is developed. Using Matlab®, a denoising methodology for the interference pattern generated during data acquisition is created, based on a stationary wavelet transform. The unwrapped image is calculated using the CPULSI (Calibrated Phase Unwrapping based on Least-Squares and Iterations) algorithm as it gives the fastest results among the tested methods. The unwrapped phase is then transformed into surface displacement. This process performs these steps for each interferogram automatically. It allows access to 2D or 3D deformation maps.

Applications of energy dispersive X-ray fluorescence technique in metallic cultural heritage studies

• Synthesise the physical principles of EDXRF and compare different spectrometers. • Review the applications of EDXRF in the study of metallic heritage pieces. • Discuss about the advantages and limitations of the technique through case studies. Cultural heritage is a legacy that allows the expression of values and characteristics of different civilisations over time. Thus, the study of those artworks and their conservation is of paramount importance. In particular, the preservation and restoration of metallic artefacts is a challenge, as these materials are often subjected to corrosion and degradation, originating complex multilayered structures. Characterising materials that compose metallic artworks, as well as possible corrosion products, is extremely useful to understand the composition and evolution of their surface, guiding conservation and restoration procedures that are adapted for each piece. This characterisation must be selective, that is, allow for differentiating all the compounds present in the piece. Ideally, the characterisation technique used for the analysis should be non-destructive and should not modify aesthetic aspects of the artwork's surface. Portable techniques are also a desirable option, as they allow the characterisation of pieces that cannot be moved to a laboratory or sampled. In this context, X-ray fluorescence spectroscopy is a powerful tool that has been used by researchers and conservators in the characterisation of metallic materials and their corrosion products. In this paper, we review the principles, advantages and limitations of energy dispersive X-ray fluorescence spectroscopy applied to metallic cultural heritage studies.

Historical proteinaceous-based pictorial binders’ analysis: a novel proteomic minimally invasive approach

Abstract Operating micro-invasive sampling when dealing with the chemical investigation of precious historical works of art is, without doubts, mandatory. Recently, scientific research in the field of Cultural Heritage has been often devoted to the development of innovative strategies for quasi non-invasive sampling on works of art to extract, for example, proteins and/or lipids composing the pictorial binders gaining extensive awareness about the materials employed by the artist. In this work, we propose a novel minimally invasive method for the sampling and characterization of protein-based painting binders. We apply a hydrophilic gel, previously functionalized with trypsin and chymotrypsin, on the artwork surface to perform an in-situ digestion of proteinaceous binders. Peptides are identified by means of a proteomic bottom-up approach combined with a high resolution/accuracy mass spectrometry technique. A wooden polychrome statue belonging to the XV century was chosen as a sample to assess the proposed protocol on a historical painting layer, as illustrated herein.

Thymus vulgaris Essential Oil and Hydro-Alcoholic Solutions to Counteract Wooden Artwork Microbial Colonization

Aromatic plants represent a source of natural products with medicinal properties, and are also utilized in the food and pharmaceutical industries. Recently, the need for eco-compatible and non-toxic products, safe for both the environment and human health, have been proposed for the sustainable conservation of historic–artistic artifacts. In this study, in order to counteract microbial colonization (Aspergillus sp., Streptomyces sp., Micrococcus sp.) on wooden artwork surfaces, Thymus vulgaris L. (Lamiaceae) essential oil (EO) and hydro-alcoholic (HA) solutions were applied in a polyphasic approach. The antimicrobial activities of EO and HA solutions were preliminarily assessed by agar disc diffusion (ADD) and well plate diffusion (WPD) in vitro methods, defining the specific concentration useful for bacterial and fungal genera, identified by optical microscopies, in vitro cultures (nutrient or Sabouraud agar), and DNA base molecular biology investigations. Specifically, the microbial patina was directly removed by a hydro-alcoholic solution (while evaluating the potential colorimetric change of the artwork’s surface) combined with exposure to EO volatile compounds, performed in a dedicated “clean chamber”. This study proposes, for the first time, the combined use of two plant extracts to counteract microbial development on wooden artworks, providing supplementary information on these products as bio-agents.

Experiencing the Untouchable: A Method for Scientific Exploration and Haptic Fruition of Artworks Microsurface Based on Optical Scanning Profilometry

The experience of an object derives not only from the sight but also from the touch: a tactile exploration can reveal the smallest information trapped within the surface up to our tactile detective threshold. Starting from the importance of this observation in the case of works of art, this research demonstrates the use of conoscopic holography sensors for high-quality acquisition of the surface of artworks (up to the micro-scale) suitable also to 3D printing. The purpose is twofold, allowing for the tactile use of the artwork, which is otherwise impossible, for visually impaired people and for new use in regard to scientific information purposes. In detail, the workflow to obtain a 3D printed replica of multiscale and polychrome artworks suitable for the haptic fruition is validated, but the potential of the tool as an innovative resource for scientific visualization of the microsurface of the artwork for conservation issues is also demonstrated. The validation was performed on notable Italian masterpieces, such as Donatello’s “Death Cristh” bronze relief in Padua and the Tintoretto painting “St. Martial in Glory with the Saints Peter and Paul” in Venice.

Measuring the BRDF and radius of curvature with patterned illumination

In this study, we propose a method to measure simultaneously the bidirectional reflectance distribution function (BRDF) and the radius of curvature of a curved surface. The surfaces of pre-molded products or artworks are not always flat. The measurement targets were a planar surface and convex surfaces with constant radiuses of curvature. We developed and experimented with an apparatus that uses patterned illumination and a collimator optical system. The results show that BRDF and radius of curvature can be measured on a curved surface. In future work, we are developing a method to accurately estimate the BRDF of a planar surface from the measured BRDF and radius of curvature.

Viable and not viable spore concentrations in National Gallery of Umbria (Italy)

The conservation actions towards artworks holding a common patrimony for the community are of primary importance, but also those related to their "container" as museums, libraries or archives are to consider. Fungal spores and bacteria carried by air flows to the artwork surface can colonize it causing biodeterioration through physical and/or chemical alterations of the materials with the irreversible loss of their value. The quality control of the indoor air surrounding the historic building is essential, as well as for the protection and conservation of the artwork, also for the protection of the health of operators and visitors. The aim of this study was to monitor airborne fungal particles, through volumetric spore traps, for improving the knowledge about the conservation and protection of artworks in the museum environment analysing the principal relationships between indoor environmental conditions and potentially biodeteriogen fungal spore growth. The evidence of no significant relationships between spore concentrations and environmental conditions recorded inside the different expositive rooms testified the regular and correct maintenance of the air conditioning system inside the considered building (National Gallery of Umbria, central Italy). Moreover, in a specific museum room a significant spore concentration decreasing trend was recorded mainly due to a structural modification in the same building.

Characterization of polyvinyl alcohol-borax/agarose (PVA-B/AG) double network hydrogel utilized for the cleaning of works of art

Since cleaning of artworks may cause undesirable physicochemical alterations and is a nonreversible procedure, it is mandatory to adopt the proper cleaning procedure. Such a procedure should remove undesired materials whilst preserving the original surface. In this regard, numerous gels have been developed and exploited for the cleaning of various artwork surfaces. Lately, agarose (AG) and polyvinyl alcohol-borax (PVA-B) hydrogels have been widely employed as cleaning tools by conservators. Both hydrogels show some limitations in specific cleaning practices. In this work, we investigated the influence of including increased levels of agarose into PVA-B systems. For this reason, we performed a detailed characterization on the double network (DN) hydrogel including the chemical structure, the liquid phase retention, the rheological behavior, and the self-healing behavior of various PVA-B/AG double network hydrogels. These new hydrogels revealed better properties than PVA-B hydrogels and obviated their limitations. The inclusion of AG into PVA-B systems enhanced the liquid retention capacity, shape-stability, and mechanical strength of the blend. Furthermore, AG minimized the expelling/syneresis issue that occurs when loading PVA-B systems with low polarity solvents or chelating agents. The resultant double network hydrogel exhibits relevant self-healing properties. The PVA-B/AG double network is a new and useful cleaning tool that can be added to the conservators’ tool-kit. It is ideal for cleaning procedures dealing with porous and complex structured surfaces, vertical surfaces and for long time applications.

Lucio Fontana and the light: Spectroscopic analysis of the artist's collection at the National Gallery of Modern and Contemporary Art.

In this work the results deriving from the characterization of materials used by Lucio Fontana to realize some of his artworks are presented. Specifically, object of analyses are three artworks from the collection of National Gallery of Modern and Contemporary Art in Rome, whose complex composition required the combination of different diagnostic techniques for a complete characterization. Microscopic fragments from the artworks were analyzed through X-Ray Fluorescence (XRF), Fourier Transformed InfraRed (FTIR) spectroscopy, in transmission and in Attenuated Total Reflectance (ATR) mode, and Raman spectroscopy to obtain information on the atomic and molecular species and to individuate pigments and binders. In one case, the richness in different materials and the not homogenous distribution on the artwork surface required the additional use of portable techniques, as Visible Light Reflectance and Raman spectroscopies with optical fiber probes, to map the surface. The combination of these techniques resulted to be a powerful tool in order to obtain a complete characterization of artist's choices and provided new information to understand the evolution of his technique.

Importance of using Nanomaterials in Preservation of Oil Paintings for Achieving Required Sustainability

New nano-materials and responsive systems have been developed and experimented for using it in preservation of artworks. as same as cleaning, deacidification and consolidation. The main goal of this study was to learn the importance of applications of nanomaterial's in preservation efficiency on oil paintings. This study will focus on Nanoscience to discover new behaviors and properties of materials at the atomic scale to create materials, devices, or systems with new properties and/or functions, will present types of nanomaterials " Carbon-based Materials - Metal-based Materials - Dendrimers - Composites " after that will present nanomaterials properties as a" structure - thermal - chemical - electrical - magnetic - electronics- biological " . the experiments in this study showing applications for nanomaterials in the preservation of oil paintings as a unique property of nanomaterials encourage and achieving sustainability concepts in the preservation of cultural heritage. Confirmed this study's effectiveness of using nanomaterials components in preservation and conservation of oil paintings within process (Cleaning – Consolidation - PH Treatment ). It was observed that there are Highly viscoelastic HVPDs and magnetic gels are very promising materials for cleaning movable artworks surfaces, Silver NPs achieved better results than zinc oxide NPs. Application of 1.0 or 2.0 mM silver NPs exhibited the best preservation effect on achieving 100% microbial inhibition (bacteria and fungi, respectively), acidic character of CCNF and CNC may not induce any problems during Treatment Process

Energy optimization of a light projection system for buildings that virtually restores artworks

The need to achieve energy efficiency standards in the lighting systems of buildings makes it necessary to optimize all aspects of them. Here, the development of a light projection system that achieves this goal by studying and modifying the spectral output, compared to conventional illumination, is described. A lighting system that estimates the reflectance characteristics of artwork and emits optimized lighting can reduce light absorption. A damage-minimizing point-by-point light projection system is developed using an optimization algorithm, to improve the appearance of the surfaces of artworks whose color has faded. In this case, a simulation of an aged oil painting was made by manipulating the original photograph, which was printed and to which the proposed system was applied. The results show that, when the aged printed image is illuminated with the optimized light source, it appears indistinguishable from the non-aged oil painting.

Fungal assessment on storerooms indoor environment in the National Museum of Fine Arts, Cuba

The artworks that are preserved in museums can be damaged by fungi when the conditions of temperature and humidity are adequate to accelerate their growth. This is increased in Cuba by the climatic conditions of the country, characterized by high temperature and relative humidity during the all year. These fungi do not only cause the artworks biodeterioration but also affectations in the personnel’s health. The aims of this work were to characterize the mycobiota in two microenvironments of the National Museum of Fine Arts, Cuba (1: three interior environments of repositories or storerooms and 2: six surfaces of artworks) and analyze its relationship with the conservation of artworks. Environmental samples were taken using a SAS Super 100 biocolector, while samples from the artworks surfaces were taken using sterile cotton swabs. Appropriate selective culture media were used to isolate fungi. The concentrations obtained in the indoor environments indicate that one storeroom was contaminated, while the other two were not. Fourteen filamentous genera, one genus of yeast, and two fungal mycelia were detected in the air of the storerooms, while four filamentous genera and one genus of yeast were obtained from the artworks studied. Aspergillus spp. was the predominant genus in the two microenvironments. Six species of the Aspergillus genus (A. glaucus, A. flavipes, A. niveus, A. proliferans, A. conjunctus, A. restrictus, A. janus) and three genera (Botryoderma, Hansfordia, Nodulisporium) detected in the repositories air as well as four isolated genera of artworks (Olpitrichum, Verticillium, Engyodontium, Tritirachium) are new findings for Cuban museums.

Art-omics: multi-omics meet archaeology and art conservation.

SummaryMulti‐omics can informally be described as the combined use of high‐throughput techniques allowing the characterization of complete microbial communities by the sequencing/identification of total pools of biomolecules including DNA, proteins or metabolites. These techniques have allowed an unprecedented level of knowledge on complex microbial ecosystems, which is having key implications in land and marine ecology, industrial biotechnology or biomedicine. Multi‐omics have recently been applied to artistic or archaeological objects, with the goal of either contributing to shedding light on the original context of the pieces and/or to inform conservation approaches. In this minireview, we discuss the application of ‐omic techniques to the study of prehistoric artworks and ancient man‐made objects in three main technical blocks: metagenomics, proteomics and metabolomics. In particular, we will focus on how proteomics and metabolomics can provide paradigm‐breaking results by unambiguously identifying peptides associated with a given, palaeo‐cultural context; and we will discuss how metagenomics can be central for the identification of the microbial keyplayers on artworks surfaces, whose conservation can then be approached by a range of techniques, including using selected microorganisms as ‘probiotics’ because of their direct or indirect effect in the stabilization and preservation of valuable art objects.

Yellowing of laser-cleaned artworks: Formation of residual hydrocarbon compounds after Nd:YAG laser cleaning of gypsum plates covered by lamp black

Abstract The removal of black crusts decaying the surface of artworks is an important concern for the conservation of cultural heritage. Nd:YAG laser cleaning of encrusted stones and plasters at 1064 nm is widely recognized as an effective restoration technique, but induces a noticeable yellowing of the treated surface. Several researches carried out on the effects of laser cleaning have been focused on the induced yellowing and how to visually mitigate this phenomenon. To this end, UV-B radiations were successfully used to lessen the laser-induced yellowing due to the removal of lamp black particles on gypsum. The mechanism at play for both the formation of the compounds yellowing the surface and their disappearance upon UV-B exposure remains, however, poorly understood. Within the frame of this research, we apply surface-sensitive characterization techniques to analyze the yellowed surface produced after Nd:YAG Q-Switched laser cleaning of lamp black deposit on a gypsum plate, and the same surface after UV-B exposure. A combination of X-ray photoelectron spectroscopy and Fourier-transformed infrared spectroscopy has been used to identify the residual carbon compounds responsible for the yellow coloration of the substrate. A nanoscale structural description of the ejected particles collected during the laser cleaning was finally performed with transmission electron microscopy. We found that the yellowing is due to partially oxidized hydrocarbons compounds deposited at the surface of the gypsum substrate. We propose that they form by reactions between carbon species emitted by the vaporization of the carbon particles, with hydrogen and oxygen produced by the dissociation of water molecules coming together from dehydration of the gypsum surface and from the water sprayed by the operator during cleaning.

The Queer Temporality of CandidaHomo Biotechnocultures

ABSTRACTThis article weaves together microsocial interactions, evolutionary theories of community and queer understandings of family, kinship and intimacy to grasp some of the complex microbiopolitics of the CandidaHomo ecology. I discuss contemporary scientific understandings of Candida albicans sociality as highly tactile and sensual, bodies constantly in touch with surfaces – chemicals, cells, tissues, prosthetics. I explore the highly contested field of evolutionary theories of social selection, including biogenetic kin selection and its biases about reproduction, intimacy and care. CandidaHomo ecologies are woven through queer kinship that is biological, but not genetic; embodied, but not essentialist. Queer communities, founded on choice and more-than-biological recognition, are considered as an alternative to dominant gene-centric kinship theories. These communities are intimate, performative and more-than-human, emerging from necessity and constantly co-created. However, homonormativity and biogenetic exclusion lurk in the closet of contemporary families of choice. I consider Luce Irigaray’s figuration of eros as a visceral and tactile reorientation of relatedness and care towards CandidaHomo kind, always already formed through impersonal intimacies and caresses. Finally, the artwork Surface Dynamics of Adhesion (2015) is discussed as a material-semiotic resolution and ‘technology’ for making kin, as Donna Haraway might say.

Smart Portable Devices Suitable for Cultural Heritage: A Review.

This article reviews recent portable sensor technologies to apply in the Cultural Heritage (CH) fields. The review has been prepared in the form of a retrospective description of the sensor’s history and technological evolution, having: new nanomaterials for transducers, miniaturized, portable and integrated sensors, the wireless transmission of the analytical signals, ICT_Information Communication Technology and IoT_Internet of Things to apply to the cultural heritage field. In addition, a new trend of movable tattoo sensors devices is discussed, referred to in situ analysis, which is especially important when scientists are in the presence of un-movable and un-tangible Cultural Heritage and Art Work objects. The new proposed portable contact sensors (directly applied to art work objects and surfaces) are non-invasive and non-destructive to the different materials and surfaces of which cultural heritage is composed.