Diego Ivan Quintero Balbas

Scopus Publications

High-lateral resolution image recovery and degradation mapping of daguerreotypes using mobile reflectance, μ-XRF, MA-XRD, and benchtop μ-vibrational spectroscopies
Diego Quintero Balbas, Eva Luna Ravan, Michela Botticelli, Claudia Caliri, Teresa Brancolini, Andrea Cagnini, Francesco Paolo Romano, Jana Striova
Talanta, 2026
The study of daguerreotypes, one of the earliest photographic process, requires analytical methods that address both their metallic composition and the high spatial resolution of their images. This work presents results obtained with research-grade laboratory instruments for image recovery and chemical characterization of degraded daguerreotype plates. Our methodology combines two transportable instruments with high lateral resolution for the image recovery: reflectance imaging spectroscopy (RIS) in the visible and near-infrared (Vis-NIR) ranges (400-2500 nm, lateral resolution 125 μm), which was used to study the optical properties of the plate, and micro-X-ray fluorescence (μ-XRF) mapping (lateral resolution ≤40 μm), which provided chemical information at spatial resolution comparable to synchrotron-based μ-XRF (10-50 μm) while offering the practical advantage of laboratory and field analysis, free from the limitations of large-scale facilities. Additionally, macro-X-ray diffraction (MA-XRD) and micro-vibrational spectroscopy (μ-Raman and μ-FTIR in reflection mode) mapping were applied to investigate, at a mesoscale, specific regions of interest (ROIs) to deepen the chemical characterization of the copper corrosion products, such as formates and oxides, present on the surface. Spot-wise micro-confocal-XRF (C-XRF) was used to study the stratigraphic distribution of elements in the plate to understand the corrosion mechanism. Our findings demonstrate the capabilities of image recovery with RIS, particularly in the NIR spectral range, and μ-XRF in tracing the Hg-L spatial distribution. This multi-scale methodology, combining macro-, meso-, and spot-wise scales, is particularly useful for documenting the image condition across the entire plate and for mapping the distribution of degradation products in regions of interest (ROIs). Such information is crucial for guiding conservation strategies in daguerreotype collections.
Designing a FAIR Catalogue of Services for the Heritage Science community
Laura Benassi, Jana Striová, Diego Quintero Balbás
Open Research Europe, 2026
Background: The European Research Infrastructure for Heritage Science (E-RIHS), recently granted with European Research Infrastructure Consortium (ERIC) legal status, aims to advance research by facilitating access to cutting-edge scientific services and tools in the domain of heritage science. One of the major challenges and achievements during its implementation phase (2022-2024, G.A. 101079148) was the creation of the Catalogue of Services (CoS)-a digital platform that helps users find, request, and manage access to both physical and digital services offered by E-RIHS partners. Method: This paper introduces the concept, design, and development of the E-RIHS CoS, emphasising how it follows FAIR (Findable, Accessible, Interoperable, Reusable) and Open Science principles. Built with a strong focus on real research needs, the platform features a flexible and scalable architecture. It includes tools like semantic search, automated workflows, and customized dashboards based on user roles. The paper also places the CoS in the broader context of similar platforms from other research infrastructures, and point out its novel features-such as a recommendation engine, multilingual support, and advanced data analytics. Results and Conclusions: Now, the E-RIHS CoS is online, providing a single access entry to E-RIHS ERIC services and making easy to find and select the most adequate scientific services based on the users' research questions. It is a solid and forward-thinking digital tool designed to support high-quality research, foster collaboration, and make heritage science more inclusive and accessible.
How to approach long-term monitoring of chemical dynamics in oil paintings?
Jorien R. Duivenvoorden, Piotr Targowski, Marcin Sylwestrzak, Magdalena Iwanicka, Jana Striova, Diego Quintero Balbás, Antonina Chaban, Raffaella Fontana, Francesca Rosi, Francesca Sabatini, Laura Cartechini, Brenda Doherty, Letizia Monico, Mixon Faluweki, Patrick Atkinson, Chi Shing Cheung, Haida Liang, Joshua A. Hill, Donata Magrini, Georgios Karagiannis, Stamatios Amanatiadis, Joen J. Hermans, Katrien Keune
Npj Heritage Science, 2025
Long-term condition monitoring of works of art can provide new insights into object-specific deterioration mechanisms. Detecting change over time allows us to determine whether deterioration is active, to investigate its cause and to establish the efficacy of conservation interventions. However, long-term condition monitoring poses both logistical and technical challenges. To address the latter, a 6-month pilot study using model systems has been performed to investigate the approach to long-term monitoring of chemical dynamic processes in oil paintings. The focus was placed on metal soap protrusions: a condition phenomenon encountered in oil paintings that results from dynamic chemical pigment-binder interactions. Eight portable non- or minimally invasive examination technologies available via the MOLAB facility of IPERION HS were used to detect change in model systems. These model systems were designed to form lead soap protrusions in situ in a short time frame by including reactive components in their stratigraphy, providing changes on a scale more typical of years or decades in real paint systems. Raking light imaging or commercial colorimetry did not provide sufficient resolution for detecting small-scale changes associated with lead soap protrusions. X-radiography with consistent acquisition parameters in combination with a form of automated recognition of protrusions was found to provide a relatively accessible method for monitoring changes in the spatial distribution of protrusions. 3D techniques such as optical coherence tomography and micro-profilometry were found to be suitable for detecting change in lead soap protrusions, provided that they reach sufficient spatial resolution in the plane of a paint layer (≤20 μm) and depth (≤2–3 μm). Acoustic microscopy was found to provide insufficient spatial resolution for this purpose. More specificity for lead soaps was provided by techniques that couple high resolution 2D or 3D imaging to spectral information, such as micro-profilometry coupled to VIS-NIR spectroscopy.
Multimodal optical approach for cultural heritage characterisation: 3D scanning and spectral mapping techniques
Valentina Righetti, Luca Pezzati, Diego Quintero Balbas, Antonina Chaban, Silvia Innocenti, Jana Striova
Proceedings of SPIE the International Society for Optical Engineering, 2025
In recent years, an increasing number of advanced instruments has been employed for the scientific investigation of cultural heritage artefacts, triggering the development of sophisticated processing tools for data analysis. The growing complexity and diversity of materials, along with the need for non-invasive and highly accurate measurement techniques, have driven significant advancements in optical metrology. This field now plays a crucial role in developing innovative solutions that combine precision, efficiency, and adaptability to diverse challenges in the documentation, conservation, and restoration of cultural heritage. A robust methodology for the detailed morphologic and compositional characterization across extensive surface areas relies on the combination of 3D surface scanning and chemical mapping techniques. This approach provides a multi-scale understanding of artefacts, capturing both topographical and chemical features critical for conservation and restoration purposes. Among the various optical methods and instruments developed at the National Institute of Optics (CNR-INO, Florence, Italy), macro-Raman mapping has proven to be a valuable tool for spatially resolved chemical analysis. The coupling of spectral mapping with tailored 3D-scanning technologies not only enhances the spatial registration of chemical data but also facilitates the correlation with other optical modalities, such as multispectral and hyperspectral imaging. These integrated methodologies contribute to a more comprehensive and data-driven approach to cultural heritage diagnostics, enabling tailored conservation strategies that consider the characteristics and complexity of artefacts. Here, we demonstrate how such multimodal, hardware-registered data, when further processed using advanced univariate analytical methods, provide comprehensive insights into the material composition and degradation processes of cultural heritage objects.
Setting up a methodology for restoring degraded daguerreotypes using UV lasers and atmospheric non-thermal plasma cleaning techniques
Diego Quintero Balbas, Evdoxia Dimitroulaki, Kristalia Melessanaki, Barbara Cattaneo, Andrea Cagnini, Laura Bartoli, Emanuele Verga Falzacappa, Paolo Scopece, Paraskevi Pouli, Jana Striova
Journal of Cultural Heritage, 2025
• UV laser and plasma cleaning practices effectively remove tarnish from daguerreotypes. • Plasma cleaning is fast and selective but less effective for complex degradation layers. • The fs KrF excimer laser at 248 nm ensures safe and controlled cleaning. • A combined laser-wet method enhances cleaning efficiency. • Combining laser and plasma cleaning might optimize tarnish removal. Since the early years of the development of daguerreotypes – the first commercial form of photography made public in 1839 – cleaning procedures have been necessary due to their tendency to tarnish. Cleaning daguerreotypes is challenging, and conventional methods often result in undesirable effects or prove impractical, especially for hand-colored plates. In recent decades, advanced techniques, such as laser and plasma cleaning, have been optimized for tarnish removal. However, their effectiveness in removing other substances, such as by-products of previous cleaning treatments, has not been evaluated. To address this issue, we investigated the efficacy of laser and atmospheric non-thermal plasma cleaning on two 19th-century daguerreotypes exhibiting two different degradation conditions: one with typical tarnish, and the other with a complex layer composed of cyanides, calcium carbonate, and an organic compound, likely produced during a previous cleaning attempt. This work reports systematic tests using visible (VIS) and ultraviolet (UV) lasers emitting at four different wavelengths: Nd:YAG (532 nm, 355 nm), KrF excimer (248 nm), and ArF excimer (193 nm). All the lasers operated in the nanosecond regime, except for the KrF excimer laser, which was also tested with femtosecond (500 fs) pulse duration. This is the first report of results using the 248 nm wavelength in both ns and fs regimes for daguerreotype restoration. For comparison, we also applied atmospheric non-thermal plasma cleaning to both types of degradation. The experiments allowed us to assess the advantages and limitations of both techniques, showing that both are suitable depending on the specific surface condition. Additionally, we evaluated a combined cleaning strategy that involved laser and wet cleaning with two different substances – distilled water and an EDTA solution – to optimize the cleaning outcomes. To make an informed selection of the parameters and evaluate treatment efficacy, we characterized the chemical composition and morphology of the daguerreotypes and their degradation products before and after cleaning using optical microscopy, μ-Raman spectroscopy, and SEM-EDS. Besides the identification of the degradation products, the analytical results provided a critical review of previous literature on laser cleaning of daguerreotypes and supported the determination of the best experimental conditions for the safe removal of degradation layers from the surface of daguerreotypes.
Insights into the stratigraphy of gelatin-based emulsion in historical dry plate photographic negatives: A multi-analytical approach
Diego Quintero Balbas, Laura Maestro-Guijarro, Paula María Carmona-Quiroga, Mohamed Oujja, Marta Castillejo, Barbara Cattaneo, Andrea Bernardoni, Alessandra Santagostino Barbone, Andrea Cagnini, Jana Striova
Microchemical Journal, 2025
• Many efforts focus on preserving photographic collections, but research on dry plate negatives remains scarce. • Multianalytical approach allowed investigating three types of dry plate negatives. • Studying the composition and stratigraphic structure is crucial for understanding emulsion degradation. • Light absorption hampers many optical techniques, but NLOM-MPEF can overcome this limitation. This research investigates historical gelatin dry plate negatives’ chemical composition and stratigraphic structure through a comprehensive multi-analytical approach. Our methodology integrated optical and laser-based techniques, with microscopies, including Optical and Scanning Electron Microscopy – Backscattered Electrons (SEM-BSE) and Non-linear Optical Microscopy (NLOM) in its Multi-photon Excitation Fluorescence (MPEF) modality to analyze stratigraphy. MPEF enabled us to overcome the limitations associated with light absorption encountered in other optical techniques. Chemical analysis using Laser-Induced Breakdown Spectroscopy (LIBS), Scanning Electron Microscopy – Energy Dispersive X-ray Spectroscopy (SEM-EDS), and micro-Raman spectroscopy allowed for the classification of negative types based on specific compositional materials, such as synthetic dyes. Our findings contribute to the knowledge of dry plate negative composition and stratigraphy, the aspects that have seldom been investigated. The information retrieved is crucial for understanding the realization and degradation mechanisms of these valuable artifacts, often prone to delamination and flaking, and can inform conservators to better treat historical dry plate photographic negatives.
3D scanning of daguerreotypes
Diego Quintero Balbas, Luca Pezzati, Barbara Cattaneo, Valentina Righetti, Jana Striova
Jphys Photonics, 2024
Daguerreotypes are historical photographic images made on mirror-like metallic plates. These are heritage objects whose shape cannot be measured with invasive techniques, like contact probes, but the high reflectivity of their surfaces makes the use of non-invasive, 3D-measuring optical techniques challenging. Moreover, the dark areas resulting from their degradation produce a very high contrast, which add extra difficulties to their measurement. In the last few years, several strategies have been developed to overcome the limitations of optical techniques when measuring reflective metallic surfaces. Many of these solutions are not applicable to the study of cultural heritage artifacts, as they are invasive. We attempted the use of conoscopic holography in a 3D-scanning system using a double-exposure strategy. This is a promising option for 3D measuring of daguerreotypes, as we experimentally demonstrated in this work. We present the results obtained from the analyses of two 19th-century daguerreotypes with different superficial conditions. The double-exposure allowed us to obtain high-quality data from the entire object surface. This enabled the measurement of micro-scale details related to the manufacturing process and/or to the corrosion deposits. The proposed methodology can be exploited to monitor the overall health of highly reflective metallic objects but also the outcomes of some conservation treatments, such as cleaning.
Non-invasive stratigraphic analyzes of gelatine-based modern painting materials with linear and nonlinear optical methods
Diego Quintero Balbas, Laura Maestro-Guijarro, Paula María Carmona-Quiroga, Mohamed Oujja, Marta Castillejo, Francesca Bettini, Simone Porcinai, Jana Striova
Jphys Photonics, 2024
Stratigraphic analyzes of polychrome surfaces, such as paintings, often need samples to offer consistent results regarding the sequence and composition of the layers. Non-invasive methodologies based on linear and nonlinear optical techniques limit material removal from the objects. Recently, optical coherence tomography (OCT) has become the preferred choice of heritage scientists because it is a safe and fast alternative for studying transparent or semi-transparent layers. Yet, nonlinear optical microscopy (NLOM)) technique in its modality of multiphoton excitation fluorescence (MPEF) has emerged as a promising tool for the same purpose. Here, we explored linear (OCT and confocal Raman microspectroscopy (CRM)) and nonlinear (NLOM-MPEF) optical methods’ capability to investigate gelatine-based layers in mock-up samples and a painting dated 1939 by an artist from the Surrealistic entourage. The optical behavior of mock-up samples that imitate the painting stratigraphy and of six painting fragments detached from the support was also investigated with fiber optics reflectance spectroscopy and laser induced fluorescence (LIF). Thickness values from the mock-ups obtained with OCT, CRM, and MPEF have provided evidence of the complementarity, from a millimetric to a micrometric scale, and the limitations (e.g. strong fluorescence emission in CRM) of the methods. Moreover, the presence of gelatine was ascertained by LIF spectroscopy applied to the painting fragments and NLOM-MPEF confirmed its suitability as a non-invasive technique for investigating gelatine-based stratigraphic systems.
Historical Pigments and Paint Layers: Raman Spectral Library with 852 nm Excitation Laser
Silvia Innocenti, Diego Quintero Balbas, Monica Galeotti, Andrea Cagnini, Simone Porcinai, Jana Striova
Minerals, 2024
Raman spectroscopy (RS), for its robust analytical capabilities under constant development, is a powerful method for the identification of various materials, in particular pigments in cultural heritage. Characterization of the artist’s palette is of fundamental importance for the correct formulation of restoration intervention as well as for preventive conservation of artworks. Here we examine the number and variability of research studies exploiting Bravo handheld Raman spectrophotometer relying on the excitation of Raman signal with temperature-shifted diode lasers emitting at 852 and 785 nm. To this end, we explore the spectral features of common historical pigments examined as powders and in the paint layer. We show that some materials may exhibit slightly different spectra as concerns especially the relative intensity of Raman lines with 852 nm laser excitation wavelength as compared to the standard 785 nm. The aim is to provide the research community with a reference spectral database that facilitates the identification of unknown pigments using the 852 nm excitation source.
Surface-enhanced Raman spectroscopy for madder lake detection in painting layers
S. Innocenti, M. Ricci, D. Quintero Balbas, R. Fontana, J. Striova, M. Becucci
European Physical Journal Plus, 2023
Madder lake is the most utilized anthraquinone dyestuff in artworks. Its main constituents (alizarin and purpurin, together with other natural dyes) form an organometallic complex (the lake) insoluble in water by precipitation or adsorption of the dye onto an inorganic substrate. Raman spectra of madder lake are strongly affected by fluorescence, making its identification by Raman spectroscopy difficult or impossible. In this work, we prepared different lakes according to historical recipes and characterized them with X-ray diffraction (XRD), IR, and UV-Visible spectroscopies. Additionally, painting mock-ups were prepared and the lakes were extracted with hydrated and ethanol-rich agar gel beads. This work is aimed at showing the advantages and limits for the identification of the madder lake constituents by Raman and SERS (Surface-Enhanced Raman Spectroscopy) methods in the hydrogels used for sample micro-extraction. The main advantage of SERS for madder lake detection is to allow the user to acquire spectra in random spots in the gel bead, without the need for recrystallized grain localization in the dried hydrogel.
The Degradation of Daguerreotypes and the Relationship with Their Multi-Material Structure: A Multimodal Investigation
Diego Quintero Balbas, Barbara Cattaneo, Andrea Cagnini, Paolo Belluzzo, Sandra Rossi, Raffaella Fontana, Jana Striova
Sensors, 2023
Non-invasive contactless analysis of an early drawing by Raffaello Sanzio by means of optical methods
Diego Quintero Balbas, Alice Dal Fovo, Letizia Montalbano, Raffaella Fontana, Jana Striova
Scientific Reports, 2022
Analytical studies on commercial artists’ colour charts from Das Deutsche Farbenbuch (1925)—identification of synthetic and natural organic colourants by Raman microscopy, surface-enhanced Raman spectroscopy and metal underlayer ATR-FTIR spectroscopy
Clarimma Sessa, Christoph Steuer, Diego Quintero Balbas, Giorgia Sciutto, Silvia Prati, Heike Stege
Heritage Science, 2022
The Colors of the Butterfly Wings: Non-Invasive Microanalytical Studies of Hand-Coloring Materials in 19th-Century Daguerreotypes
Diego Quintero Balbas, Barbara Cattaneo, Andrea Cagnini, Paolo Belluzzo, Silvia Innocenti, Sandra Rossi, Raffaella Fontana, Jana Striova
Heritage, 2022
Nonlinear imaging and vibrational spectroscopic analysis of cellulosic fibres treated with COEX® flame-retardant for tapestry preservation
Alice Dal Fovo, Jana Striova, Diego Quintero Balbas, Sara Mattana, Niccolò Tacconi, Riccardo Cicchi, Raffaella Fontana
Rsc Advances, 2022
Non-Invasive Evaluation of Polymeric Protective Coatings for Metal Surfaces of Cultural Heritage Objects: Comparison of Optical and Electromagnetic Methods
Diego Quintero Balbas, Alice Dal Fovo, Daniela Porcu, Antonina Chaban, Simone Porcinai, Raffaella Fontana, Jana Striova
Applied Sciences Switzerland, 2022
Portable Sequentially Shifted Excitation Raman Spectroscopy to Examine Historic Powders Enclosed in Glass Vials
Silvia Innocenti, Diego Quintero Balbas, Luca Pezzati, Raffaella Fontana, Jana Striova
Sensors, 2022
Evaluation of an eco-friendly flame retardant treatment applied to cellulosic textiles used for the conservation of historical tapestries
Diego Quintero Balbas, Claudia Cirrincione, Marta Cimò, Giancarlo Lanterna, Benedetto Pizzo, Raffaella Fontana, Jana Striova
Polymer Degradation and Stability, 2022
Noninvasive identification of turmeric and saffron dyes in proteinaceous textile fibres using Raman spectroscopy and multivariate analysis
Diego Quintero Balbas, Giancarlo Lanterna, Claudia Cirrincione, Marilena Ricci, Maurizio Becucci, Raffaella Fontana, Jana Striova
Journal of Raman Spectroscopy, 2022
Non-invasive identification of textile fibres using near-infrared fibre optics reflectance spectroscopy and multivariate classification techniques
Diego Quintero Balbas, Giancarlo Lanterna, Claudia Cirrincione, Raffaella Fontana, Jana Striova
European Physical Journal Plus, 2022
Fluorescence Lifetime Phasor Analysis and Raman Spectroscopy of Pigmented Organic Binders and Coatings Used in Artworks
Alice Dal Fovo, Sara Mattana, Antonina Chaban, Diego Quintero Balbas, João Luis Lagarto, Jana Striova, Riccardo Cicchi, Raffaella Fontana
Applied Sciences Switzerland, 2022
Development of a multi-method analytical approach based on the combination of synchrotron radiation X-ray micro-analytical techniques and vibrational micro-spectroscopy methods to unveil the causes and mechanism of darkening of "fake-gilded" decorations in a Cimabue painting
Letizia Monico, Silvia Prati, Giorgia Sciutto, Emilio Catelli, Aldo Romani, Diego Quintero Balbas, Zelan Li, Steven De Meyer, Gert Nuyts, Koen Janssens, Marine Cotte, Jan Garrevoet, Gerald Falkenberg, Vanessa Isabel Tardillo Suarez, Remi Tucoulou, Rocco Mazzeo
Journal of Analytical Atomic Spectrometry, 2022
Holy corn. Interdisciplinary study of a mexican 16th-century polychrome maize stem, paper, and colorín wood sculpture
Diego Quintero Balbas, Esteban Sánchez-Rodríguez, Álvaro Zárate Ramírez
Heritage, 2021
Where is Dante Now? Street Art: Conservation, Rejection and Elimination. The Case of the Street Art Mosaics in Ravenna, Italy
Diego Iván Quintero Balbás
En Claves Del Pensamiento, 2020
Chemical and morphological decay in maize stem sculptures
A.A. Ortega-Ordaz, E. Sánchez-Rodríguez, L. Rojas-Abarca, J.E. Bojórquez-Quintal, A. Ku-González, C.I. Cruz-Cárdenas, D.I. Quintero-Balbás
Science and Digital Technology for Cultural Heritage Interdisciplinary Approach to Diagnosis Vulnerability Risk Assessment and Graphic Information Models Proceedings of the 4th International Congress Science and Technology for the Conservation of Cultural Heritage Technoheritage 2019, 2020
Thin-layer chromatography/metal underlayer-ATR FTIR methodology for the study of synthetic dyes extracted from degraded wool fibres
Diego Quintero Balbas, Silvia Prati, Giorgia Sciutto, Emilio Catelli, Rocco Mazzeo
New Journal of Chemistry, 2019
To be preserved or to be replaced? Contemporary religious imagery in Latin America and its conservation
Diego Iván Quintero Balbás
Studies in Conservation, 2016

Diego Ivan Quintero Balbas

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