Academy of Fine Arts Vienna

Iron-gall inks (IGI) were among the most widely used writing materials in historical manuscripts. However, their presence is now recognized as a major cause of degradation in many of these documents. Common forms of deterioration include ink fading and discoloration, embrittlement of the writing support, crack formation, and material loss. Understanding the mechanisms underlying IGI-induced degradation is therefore crucial for developing effective strategies for the preservation of historically valuable manuscripts. In this study, a systematic and multi-analytical approach, involving the use of Raman, electron paramagnetic resonance, and infrared spectroscopy, was employed to investigate the degradation processes associated with IGI, with a specific focus on their intrinsic chemical variability. Three key parameters were considered: the structure of the polyphenolic ligand, the pH, and the iron-to-ligand ratio. These variables were selected to evaluate their respective contributions to the observed degradation phenomena. The findings provide a comprehensive overview of the main degradation pathways and the factors influencing them. Among the results, some indicate the occurrence of hydrolytic processes involving the complex ligands, which seem confined to the acidic conditions applied during sample preparation. In addition, the results enabled comparison of the differences in oxidation rates observed during accelerated aging, revealing how these rates vary according to the structure of the complexes. Overall, the study establishes a robust and reproducible framework that lays the groundwork for future research on IGI-related degradation.

Generative AI is increasingly used to produce visual content for service, educational, and cultural-guide robots. Yet culturally specific prompts may be translated into a restricted set of visually recognisable cues, creating a gap between surface recognisability and culturally situated meaning. This paper examines that problem through a structured exploratory audit combining transparent corpus reporting with qualitative visual coding. The corpus contains 30 Chinese painting-related prompt groups with four documented outputs per group (120 images total), organised around three prompt forms: English descriptors, transliterated or specialist terms, and interface-oriented variants. The analysis focuses on four linked dimensions: recurrence of culturally marked visual features, interface readiness, semantic compression, and interaction risk. Three recurrent tendencies are identified: convergence on a narrow visual vocabulary centred on ink texture, misty mountains, negative space, seal-like marks, and pseudo-calligraphic forms; transformation of cultural material into polished interface surfaces; and substitution of generic cultural atmosphere for historically or aesthetically situated knowledge. The study contributes a case-grounded audit framework for distinguishing visual recognisability from cultural adequacy and for identifying representational risks before generated imagery is incorporated into HRI interfaces.

Der Text argumentiert aus praxisorientierter Perspektive, dass Kunstpädagogik ein zentraler Bestandteil von Medienbildung ist, da Kinder und Jugendliche in einer von Bildern und Algorithmen geprägten Welt lernen müssen, visuelle Darstellungen kritisch zu verstehen. Anhand eigener Unterrichtserfahrungen wird gezeigt, wie prozessorientierte, projektbasierte Ansätze in Kunst und Digitaler Grundbildung Wahrnehmung, Ausdruck und mediale Reflexionsfähigkeit fördern. Trotz struktureller Einschränkungen im Schulalltag werden fachübergreifende Schnittstellen genutzt, um ästhetische, soziale und mediale Kompetenzen miteinander zu verbinden.

Six monumental paintings by the Dutch animal painter Paulus Potter (1625–54) were examined using X-radiography to determine how his canvases were prepared, stretched and sometimes enlarged. The digitised X-radiographs were subjected to computer-assisted canvas analysis, using algorithms that produce thread density and thread angle maps. This characterised the types of supports that Potter used, the width of the fabric, how they were stretched onto wooden strainers, and which ground layers were applied. These features distinguished the two types of support. Canvases he used in his early career around The Hague (ca. 1647–51) share features that connect their preparation closely to Potter’s studio. The Bull (1647) was enlarged by the artist during the painting process. After moving to Amsterdam (1652–54), Potter employed exceptionally wide pre-primed canvases. Data from X-radiographs were complemented by analyses of cross-sections containing ground layers, and microsamples of canvas fibres from two paintings.

Cultural heritage objects can accumulate DNA from materials, environments, and repeated human contact, but biomolecular profiling of such items is constrained by nondestructive sampling requirements, ultra-low biomass, and high contamination risk. Here we present a minimally invasive workflow that integrates gentle swab collection, low-input whole-metagenome sequencing, taxonomic profiling, and Y-chromosome analyses to recover ″biological signatures of history″ from Renaissance-era artwork and archival correspondence associated with ancestors of Leonardo da Vinci. Across artifacts, we recovered heterogeneous mixtures of microbial and eukaryotic DNA (including bacteria, fungi, plants, and viruses) consistent with composite ″biomes″ that reflect differences in substrate, storage, conservation treatments, and handling. Multivariate comparisons show reproducible sample-to-sample separations. In parallel, we assessed human Y-chromosome signal using a panel of ~90,000 phylogenetically informative markers and partial Y-STR profiling where feasible. Across multiple independent swabs from Leonardo da Vinci-associated items, the obtained Y chromosome marker data suggested assignments withing the broader E1b1/E1b1b clade. However, the control samples also indicate mixed contributions consistent with modern handling and other sources. Together, these data demonstrate the feasibility as well as limitations of combining metagenomics and human DNA marker analysis for cultural heritage science, providing a baseline workflow for future conservation science studies and hypothesis-driven investigations of provenance, authentication and handling history. ### Competing Interest Statement The authors have declared no competing interest. Financial support was provided by the Achelis & Bodman Foundation, Richard Lounsbery Foundation, and Puffin Fund in the context of the Leonardo Da Vinci DNA Project.