Restoration Of Artworks Research Articles

Nanofibrous Photothermal Materials from Natural Resources: A Green Approach for Artwork Restoration.

Cleaning unwanted paint layers represents a significant challenge in cultural heritage restoration, requiring high effectiveness, spatial precision, and nontoxic techniques. Cleaning vandalic acts or street art paints is particularly challenging because of insoluble varnishes, which are very resistant to traditional removal treatments. Here, for the first time, we employ the photothermal effect for cleaning an artwork, using electrospun nonwovens incorporated with melanin nanoparticles (NPs). This material shows outstanding photothermal properties and photostability. The nonwoven incorporated with melanin NPs, in combination with a solvent, efficiently removes alkyd resin paint layers in a short time of application, with high spatial control. Moreover, an eco-compatible system is obtained by producing a nonwoven made up of a natural polymer electrospun in water, cuttlefish ink as a melanin source, and a green solvent. In summary, using the new pullulan-melanin nonwoven represents a novel and unusual application of the photothermal effect, and its fastness, effectiveness, and safety make it suitable for use in the artwork restoration field.

Developing Innovative Apolar Gels Based on Cellulose Derivatives for Cleaning Metal Artworks.

The use of organic solvents, particularly those of a non-polar nature, is a common practice during cleaning operations in the restoration of polychrome artworks and metallic artifacts. However, these solvents pose significant risks to the health of operators and the environment. This study explores the formulation of innovative gels based on non-polar solvents and cellulose derivatives, proposing a safe and effective method for cleaning metallic artworks. The study is focused on a toxic apolar solvent, Ligroin, identified as one of the most widely used solvents in the cultural heritage treatments, and some "green" alternatives such as Methyl Myristate and Isopropyl Palmitate. The main challenge lies in overcoming the chemical incompatibility between non-polar solvents and polar thickening agents like cellulose ethers. To address this problem, the research was based on a hydrophilic-lipophilic balance (HLB) system and Hansen solubility parameters (HSPs) to select appropriate surfactants, ensuring the stability and effectiveness of the formulated gels. Stability, viscosity, and solvent release capacity of gels were analyzed using Static Light Multiple Scattering (Turbiscan), viscometry, and thermogravimetric analysis (TGA). The efficacy of cleaning in comparison with Ligroin liquid was evaluated on a metal specimen treated with various apolar protective coatings used commonly in the restoration of metallic artifacts, such as microcrystalline waxes (Reswax, Soter), acrylic resins (Paraloid B44), and protective varnishes (Incral, Regalrez). Multispectral analysis, digital optical microscopy, FTIR spectroscopy, and spectrocolorimetry allowed for the assessment of the gels' ability to remove the different protective coatings, the degree of cleaning achieved, and the presence of any residues. The results obtained highlight the ability of the formulated gels to effectively remove protective coatings from metallic artifacts. Cetyl Alcohol proved to be the most versatile surfactant to realize a stable and efficient gel. The gels based on Methyl Myristate and Isopropyl Palmitate showed promising results as "green" alternatives to Ligroin, although in some cases, they exhibited less selectivity in the removal of protective coatings.

Dual attention and channel transformer based generative adversarial network for restoration of the damaged artwork

Artworks are treasures of valuable cultural and historical heritage. Artworks get damaged due to environmental and other factors. The artificial intelligence-based restoration of digitized artwork images can guide the artists in physically restoring the damaged artworks. Previous methods have not been able to restore artwork images well. This paper proposes a dual (spatial and channel) attention and channel transformer-based generative adversarial network to restore damaged artwork images digitally. The proposed generative adversarial network has spatial and channel attention layers in the encoder part of the generator and a channel transformer between skip connections from the encoder to the decoder part of the generator. Spatial and channel attention helps learn inter-spatial and inter-channel global relationships among image features. Channel transformer ensures multiscale feature fusion and reduces the semantic gap between encoder and decoder layer features. Moreover, the proposed network has been trained using a linear combination of perceptual, adversarial, and structured similarity index measure loss, which helps better train the network. Further, the proposed network has been validated on two different datasets, and the results indicate that the proposed method outperforms state-of-the-art artwork restoration methods.

Study of the two-sided icon "Pieta" / "Holy Martyr Barbara" of the 18th century from the Church of John the Baptist in the village of Dorozhiv, Drohobytsky District, Lviv Region, in the context of the separation process of paint layers and transferring them to a new base

The study is devoted to the problems of restoration of the double-sided icon "Pieta" / "Holy Martyr Barbara" using the method of separation and transfer to a new basis of easel painting. Today, the main task of the restorer is the maximum study, research and preservation of the work of art, its history and transformation over time. The article presented the possible reasons for restoration and repainting of artworks of easel painting, as well as the most widely used methods of "preservation", fixing the layers of later repaintings, which lead to their physical loss due to the discovery of an older, original painting layer. Emphasis is placed on the expediency of applying the technique of layering and transfer to a new basis of easel painting, as an alternative in the context of maximum preservation of the entire structure of the artwork, including later historical transformations. The necessary conditions that precede the successful application of the technique of separation and transfer to a new base of artworks of easel painting are specified. There are presented the general conclusions about the state of preservation and the set of conducted physical-chemical and technical-technological studies of the double-sided icon "Pieta" / "Holy Martyr Barbara" of the 18th century from the church of John the Baptist in the village of Dorozhiv, Drohobytskyi district, Lviv region, and a program of restoration activities. Tests on separation of the paint layer of the 19th century from the "Pieta" icon are presented and the obtained results were analyzed, as a result was selected the optimal method of separation of this painting layer as one whole fragment. The entire process of conservation and restoration processes, including the application of appropriate restoration methods, as well as the specifics of the selection and use of restoration materials, is presented and illustrated. The result of this research using the technique of separation is the preserved painting layer of the icon "Pieta" of the 19th century and the painting of the icon of 1726, created by Ivan Seredyskyi, an icon painter of the Rybotytsky Center of Church Art, opened for further study. Attention is drawn to the study of this icon in the context of the work of Rybotyk masters in the monograph of Roksolana Kosiv.

Development of 3D printed nanomaterials for restoration of exterior artworks

Despite the great potential of 3D printing technologies coupled with nanotechnologies, just few studies are present in the scientific literature. Application of nanocomposites materials for 3D printing in the field of cultural heritage restoration, is a promising approach to obtain novel and functionalized materials for the artworks element to be recreated. In this context, the present work aims to study innovative nanocomposites materials suitable for the considered application. A commercial PLA filament was additivated with SiC, SiO2 and TiO2 nanoparticles, synthetized by CO2 laser pyrolysis. Nanocomposite filaments were produced by a co-rotating twin-screw extruder and specimens were produced by 3D printing and analysed against their mechanical and hydrophobic properties by means of tensile tests and water absorption and contact angle measurements, respectively.

A Multi-Analytical Approach for the Characterization of Painting Materials and Metal Soap Formation in Two Artworks by the Argentinian Painter Antonio Berni

This work describes the characterization of pigments and ground layers in two paintings by the renowned Argentinian painter Antonio Berni (1905–1981). The studied paintings are “Toledo” and “Figure” from the collection of the Provincial Museum of Fine Arts in Santa Fe (Argentina). To approach this goal, an integrated investigation comprising in situ X-ray fluorescence measurements by means of a portable system (pXRF), micro-Raman spectroscopy, Attenuated Total Reflection–Fourier transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS) was carried out. The results revealed a chromatic palette with inorganic pigments, such as ultramarine blue, cobalt blue, lead white, zinc white, yellow cadmium, and hydrated chromium oxide (viridian), together with a preparation layer consisting of a mixture of earth, lead white, and calcite in “Toledo”. On the other hand, the preparation layer in “Figure” was characterized as lithopone, a mixture of barium sulfate and zinc sulfide. ATR-FTIR-analysis revealed the formation of metallic soaps in both paintings due to the reaction of fatty acids from a drying oil used as a binder with lead and zinc pigments, as confirmed by comparison with the infrared spectra of synthetic lead and zinc soaps. This study contributes to the understanding of Berni’s painting style and the future restoration of both artworks.

Characterization of ablation conditions with the grayscale representation for Nd:YAG laser to decolor the blue‐ink on marble stone surface: Decoloration dependency on the laser flux power, wavelength, and the water spraying

AbstractAiming at artwork restoration application, to decolor the blue‐ink stained marble stone surface was studied for finding out efficient ablation conditions with the use of Q‐switched Nd:YAG laser as the function of laser flux power, wavelength, and its water spray effect. The blue ink mostly consists of indigo dye which absorbs light in the visible region. The decoloration, or decolor efficiency, was evaluated by using the grayscale representation instead of the RGB method. Our experimental results show that the 532 and 355 nm wavelengths are more suitable for blue‐ink decoloration. No decoloration was observed at the 1,064 nm ablation, which is usually regarded as effective on black‐crust stained surfaces. The decolor effect of the water‐sprayed surface was found to be effective at the higher laser flux power. A photo‐absorption‐assisted laser ablation mechanism is proposed in addition to the plasma‐assisted laser ablation mechanism.

Terahertz Spectroscopic Analysis of the Minium Pigment: Evidence of Low-Temperature Phonon Splitting.

Terahertz spectroscopy has been increasingly utilized as an effective nondestructive tool for the diagnosis, analysis, and restoration of artworks. In particular, in the case of artist's pigments, the terahertz probe reveals the vibrational modes that are unique to a given pigment species under study, motivating the ongoing efforts to establish a comprehensive terahertz spectral database of representative pigments. Standard archived spectra are typically acquired at room temperature and susceptible to spectral broadening, which often renders pigment identification difficult, if not impossible. In this paper, we report the frequencies of the vibrational modes of minium (Pb3O4, red lead) by performing terahertz time-domain spectroscopy at room temperature and also at low temperatures. Clear absorption peaks appear at 54.9, 62.1, 71.3, and 83.9 cm-1 at room temperature and blue-shift as the temperature decreases. In addition, new absorption peaks of 59.8 and 66.4 cm-1 are observed below 150 K, which signify a structural phase transition occurring at 170 K in minium. Our results are expected to enhance our understanding of the vibrational activity of minium and suggest a future direction for how to improve and refine the existing terahertz spectral databases for pigment analysis.

Artwork restoration using paired image translation-based generative adversarial networks

Preservation of the artworks has historical and cultural importance. However, with time, environmental factors severely affect artworks, and these damages are often complicated to repair manually and through traditional methods. We propose a method to restore artwork that has been damaged over time. This work proposes a systematic approach using paired image-to-image translation based on a generative adversarial network. The experimental results have been quantitatively evaluated. The experimental results obtained from the presented work visually prove that the presented approach of artwork restoration completely restores the damaged artwork.

РЕПРОДУКЦІЯ ТА РЕКОНСТРУКЦІЯ МЕЗОАМЕРИКАНСЬКИХ КОДЕКСІВ: ПРОБЛЕМИ І ВИКЛИКИ

The paper meticulously analyses the developmental trajectory of the reproduction and restoration of Mesoamerican codices within the context of historical and cultural studies pertaining to the region. The significance of qualitatively documenting such sources is underscored. Various technologies employed in the creation of reproductions are tackled, and their respective advantages and disadvantages delineated. The author sheds light on the interplay between technological advancements and the progress made in historical, archaeological, and art historical studies. Specifically, it addresses the improvements in existing documentation methods and the emergence of modern techniques, coupled with the easy access to the information through the Internet. The research primarily relies on freely accessible image sources. The study examines several facsimile editions of the codices that have been published since the 19th century, paying particular attention to the reproductions of the Borgia codex. Through comparative analysis the author evaluated the quality and accuracy of these reproductions, both among themselves and in relation to the original. Additionally, the article presents the author's findings on the digital restoration of two pages of the Borgia codex, undertaken between 2021 and 2023. The manuscript reconstruction process is elucidated, accounting for factors such as image complexity and fragment preservation. Within this framework, the article unveils certain aspects of Mexican mythology and iconography, and explores different perspectives on the interpretation of several scenes depicted in the codex. The results of this study are compared with other extant restorations and reproductions, thereby substantiating their relevance and accuracy. The paper concludes by examining the present state and future prospects of using graphic editors for the restoration of artworks more generally.

Cyclododecane shaping, sublimation rate and residue analysis for the extraction of painting micro-samples from resin cross-sections

Cross-section preparation of painting micro-samples is part of their routine analysis. This type of preparation can be used for several analytical techniques, such as scanning electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, and optical microscopy. These techniques offer high-resolution imaging and/or elemental information, providing access to technical and material data important for the interpretation, preservation, and restoration of painted artworks. However, it also means that the material from the sample embedded in the resin becomes unreachable for further analysis, except for the polished surface of the cross-section. Degradation of the embedding medium can also occur over time, which can lead to misinterpretation, loss of information, or even complete destruction of the embedded sample. In the field of cultural heritage, cyclododecane (CDD) is commonly used for the consolidation and protection of objects, and is used in the preparation of cross-sections to prevent contamination of the sample by the embedding medium. This study enhanced the existing preparation process by shaping the CDD layer to enable extraction of the micro-sample from the resin if needed, without compromising the integrity of the sample. Moreover, the purity, the sublimation rate in a normal environment and a vacuum, and the impact of CDD on three different types of samples (historical painting on a canvas, wall painting fragment, model sample) were examined.

Metaverse Virtual Art Assets That Is Breaking Through the Confinement of Materials in View of Authenticity and Immortality

The conservation by the metaverse cloud computing technology that is breaking through the confinement of materials which supply the virtual art assets solve not only the debate of artwork restoration, but also the storage space for our abundant art assets. A participatory culture of the meme generation estimates that we can combine the virtual and physical artwork so as to guide the public to better understand the artwork and improve the aesthetic environment of society in the digital world. Therefore, the creator’s spirit of sacrifice for art can achieve immortality.

A metabarcoding approach for the study of biodeterioration of ancient wall paintings in an Italian cave

AbstractCaves represent unique habitats for the development of microbial communities due to particular environmental conditions. Mural paintings occurring in caves suffer from degradation caused by natural processes in which microorganisms are significantly involved. The characterization of the microbial biofilm with non-destructive analysis is important to better preserve and safeguard these artifacts. This study aimed at investigating the microbial communities colonising the frescoes in the Fornelle cave (Calvi Risorta, Caserta, Italy) using a metabarcoding approach. We found a high representation of eubacteria, followed by cyanobacteria, fungi, and microalgae. This study confirmed the potential of non-invasive techniques as DNA metabarcoding as powerful tool for conservation and restoration of artworks.

비파괴 분석법에 의한 천연석채(천연 안료)의 효율적 분석

Component analysis of pigments is very important in terms of forensic art or restoration of artworks and cultural properties. In this study, the components were analyzed by non-destructive analysis methods such as spectrophotometry, X-ray fluorescence(XRF) spectroscopy, X-ray diffraction(XRD) spectroscopy and Raman spectroscopy for 37 types of natural pigments(Natural Seokchae). The analysis found that there were some color differences depending on the type of main coloring mineral, the degree of other mineral content and the stoichiometric compositions. As a result, the constituent elements of the Natural Seokchae were determined by XRF. The coloring minerals such as azurite and lazurite(blue), malachite and celadonite(green), cinnabar and realgar(red), orpiment(yellow), goethite and hematite(brown), calcite(white), ilmenite(black), and clinochlore(gray) were determined by XRD. Raman spectra were obtained from 30 out of 37 samples; specific peaks of azurite, lazurite, malachite, cinnabar, realgar, calcite, albite, quartz and goethite were identified according to their corresponding pigments.

Emerging materiality through dynamic digital conservation

In the neuralgic field of restoration of delicate sculptural artworks, the contribution of high-precision, contactless three-dimensional (3D) recording in the documentation of their current condition and their further digital investigation are proven valuable. However, the incredible possibilities of the digital sphere oppose the limitations of the matter, raising case-specific ethical and practical issues that highlight the complexity of the restoration process. The nature of the construction material(s) of any cultural artifact determines not only their aging and deterioration ratio in relation to their exposure to environmental conditions but also the ethically acceptable and practically feasible degree of intervention for their conservation. So far, the digital conservation approaches concern artifacts made of rigid materials, such as ceramic and stone. Their very nature determines their conservation treatment in the real world and dictates their digital approach, which orbits around the repositioning of their detached fragments, the supplementation or reconstruction of their lost parts, the design of support structures for display or storage, etc.The singularity of the ‘Xenophanes’ figurine lies in its strong plasticity and the malleable contemporary construction materials (wax and plasticine), which require specialized conservation interventions to be preserved. Over time, the inclination of the figurine has changed significantly, posing stability and deformation issues; its head and stick are detached, and both hands are lost. The timeline of the weathering of this particular artwork is documented at two points in time, in 2005 and 1994.This paper presents the first stage of an ongoing investigation. It includes the documentation of the artworks with both active and passive recording methods, their post-processing methodology offering the opportunity to combine their strengths and integrate them in the resulting 3D model. This final model was subsequently used to accomplish the digital restoration of the figurine to its earlier state(s). The workflow of 3D keyframe animation facilitated the restoration of our non-rigid figurine in digital time. The complexity of the decision-making process for the digital restoration of flexible artworks is highlighted by a series of ethical and applied considerations that arise during the procedure, along with the desire for a digital 3D object that corresponds to the singularity of the authentic artwork in order to evaluate the restoration possibility of the latter. The nature and needs of the figurine studied here allow a dynamic digital post-processing conservation approach that moves beyond reassembly, and within the limits of the tolerances of its construction materials for its reformation, in order to study the restoration steps to earlier states as well as the simulation of a possible physical approach to the object. In such an approach, where the materiality and plasticity of the authentic artifact are interwoven with the protocol for the digital conservation approach, the knowledge and experience of an Information and Communication Technology (ICT) skilled conservator was instrumental.

Radiologia de tecnologia digital aplicada à pintura: avaliação da qualidade de imagens obtidas em sistemas clínicos de radiologia

Introduction: The area’s studies have a great relevance in artwork. Laboratories committed to this purpose are scarce and employ professionals without specific knowledge in handling of ionizing radiation. It is not known to what extent, in Portugal, clinical radiological centers could provide added value to technology of digital radiography applied to painting, in order to expand their business areas and the performance of radiographers, thus enhancing synergies between these two areas. Goals: It was intended to analyse a possible applicability, to painting, of the Digital Radiology systems (CR and DR), used in the clinic settings, through the evaluation of the variable “radiographic image quality”, since the systems Clinical radiological tests, with indirect or direct conversion detectors of different energies and photodetectors of the electrical signal, show significant improvements in imaging patterns. Material and Methods: 21 radiographs were obtained from exposures made over three paintings in three different radiological systems with an emphasis on exposure parameters (potential difference (kV) and current intensity (mAs)). The sample was directed to works that presented different techniques, materials and compositions and selected by a museologist. The quality of the radiographs, operationalized by the analysis’s dimensions used in the evaluation of artworks: preservation of the support; distinction of details; contrast; contour definition; creative and technical process and components / materials. Four observers (2 specialists in medical image and 2 in art), under conditions of independence, evaluated the radiographs acquired according to a 4-point Likert scale. The analysis dimensions were organized into 11 criteria and the conditions for structured observation of the radiographs were standardized for display on a 15.6 ”GeChic 1503H monitor. Results: The most graded images were obtained with the Computerized Radiography (CR) system (mode: 3) given that this technology, in the opinion of the observers, provided a better view of the analysis criteria previously defined. The results were presented using descriptive statistics and discrete categorical variables, grouped into modal classes. Conclusions: Clinical digital radiography, especially Computed Radiography (CR), applied to painting, showed considerable dimensions of image quality and its use can contribute to the conservation, restoration, validation, analytical study, dating and authentication of artworks.

Hyperspectral sensor: A handy tool to evaluate the efficacy of cleaning procedures

• ASD-FieldSpec® 3 operates VNIR and SWIR reflectance spectral range. • VNIR and SWIR provide ready-to-use information on the degree of sulphation of carbonate stone. • SWIR data allowed information on efficacy of three different cleaning techniques. • The method supports monitoring of stone alteration during restoration. In urban environments, degradation processes affecting both natural and artificial carbonate materials commonly result in the formation of sulphate-based deposits (i.e., black crusts). Hyperspectral techniques may provide ready-to-use information on the degree of sulphation of carbonate stone, hence helping to monitor the conservation state of carbonate stone monuments. In this study, the Short-Wave InfraRed (SWIR) hyperspectral technique was tested on the world-famous marble-made Loggia di Baccio d’Agnolo in Santa Maria del Fiore Cathedral of Florence (Italy), affected by extensive “black crust” formation. A SWIR method based on a portable spectroradiometer (ASD Fieldspec® 3) was applied to verify the efficacy of different cleaning methods (i.e., laser, chemical and microbial). The interpretation of the SWIR spectra was based on a full-profile approach, in which the calcite and gypsum contributions were evaluated by weighing the best fit simulated contributions of reference compounds. The technique was able to provide in real time semi-quantitative determinations of the amount of gypsum developed on the stone surface, demonstrating to be a fast and handy routine tool during restoration of artworks.

Video Inpainting: A Complete Framework

Reconstructing and repairing of corrupted or missing parts after object removal in digital video is an important trend in artwork restoration. Video inpainting is an active subject in video processing, which deals with the recovery of the corrupted or missing data. Most previous video inpainting approaches consume more time in extensive search to find the best patch to restore the damaged frames. In addition to that, most of them cannot handle the gradual and sudden illumination changes, dynamic background, full object occlusion, and object changes in scale. In this paper, we present a complete video inpainting framework without the extensive search process. The proposed framework consists of a segmentation stage based on low-resolution version and background subtraction. A background inpainting stage is applied to restore the damaged background regions after static or moving object removal based on the gray-level co-occurrence matrix (GLCM). A foreground inpainting stage is based on objects repository. GLCM is used to complete the moving occluded objects during the occlusion. The proposed method reduces the inpainting time from hours to a few seconds and maintains the spatial and temporal consistency. It works well when the background has clutter or fake motion, and it can handle the changes in object size and in posture. Moreover, it is able to handle full occlusion and illumination changes.

The Bad and the Good-Microorganisms in Cultural Heritage Environments-An Update on Biodeterioration and Biotreatment Approaches.

Cultural heritage objects constitute a very diverse environment, inhabited by various bacteria and fungi. The impact of these microorganisms on the degradation of artworks is undeniable, but at the same time, some of them may be applied for the efficient biotreatment of cultural heritage assets. Interventions with microorganisms have been proven to be useful in restoration of artworks, when classical chemical and mechanical methods fail or produce poor or short-term effects. The path to understanding the impact of microbes on historical objects relies mostly on multidisciplinary approaches, combining novel meta-omic technologies with classical cultivation experiments, and physico-chemical characterization of artworks. In particular, the development of metabolomic- and metatranscriptomic-based analyses associated with metagenomic studies may significantly increase our understanding of the microbial processes occurring on different materials and under various environmental conditions. Moreover, the progress in environmental microbiology and biotechnology may enable more effective application of microorganisms in the biotreatment of historical objects, creating an alternative to highly invasive chemical and mechanical methods.

Restoration and preventive conservation of marble artworks: the HAP4MARBLE project

The HAP4MARBLE project was funded by the European Commission within the call H2020-MSCA-IF-2014 of the Marie Skłodowska-Curie Actions (Grant Agreement n. 655239). The goal of the project was to develop an innovative conservation treatment for marble artworks exposed outdoors, which suffer from several deterioration processes predicted to be worsened by future climate change.