Studies of Early Netherlandish panel paintings have long implemented techniques such as dendrochronology, pigment analysis and infrared reflectography. However, knowledge about the production of workshop replicas from fifteenth century paintings, and later copies, remains limited. As a result, the attribution of such paintings poses a challenge to art historians. Here, we present a multidisciplinary investigation into two copies of an Early Netherlandish panel painting attributed to the fifteenth-century Flemish painter Pieter Cristus (or Petrus Christus), active in Bruges (Belgium) between c. 1445 and 1460 CE. Earlier research dated these works to the late 15th century based on dendrochronology and pigment analysis, although alternative hypotheses suggested a 17th-century origin or even modern forgery. To resolve this debate, we applied dendrochronology, radiocarbon dating, MA-XRF, infrared reflectography, Raman spectroscopy, and stylistic analysis. The new dendrochronological results, supported by radiocarbon dating, proved key in refuting the hypothesis of the 15th-century date, revealing that the trees were cut around the mid-17th century. Furthermore, while the pigments identified were largely consistent with 15th-century painting practices, the stylistic characteristics and the presence of the inscription “I.P.C” (invenit Petrus Cristi) in one of the paintings supports a production in the mid-17th century or shortly afterwards. These findings challenge the reliability of earlier dendrochronological assessments and illustrate that pigment analysis alone cannot securely date paintings, as historical materials and techniques persisted over time. Overall, our research highlights the practice of copying Early Netherlandish paintings in the 17th-century and the importance of integrated technical and art-historical approaches for accurate attribution.
This research provides new insights into the materials, methods of application and modification of the black lines used by Piet Mondrian (1872–1944) in his Neoplastic works. Interesting information was gained from letters and studio photographs, the making of mock-ups and reconstructions, and the in-depth study of four paintings, dated between 1921 and 1938, in the collection of Fondation Beyeler (Riehen/Basel, Switzerland)—Tableau I (1921–1925), Composition with yellow and blue (1932), Composition with double line and blue (1935) and Picture no. III (1938)—as well as the examination of an unfinished painting, Composition with red (1934, private collection). The four paintings were investigated with high-magnification stereomicroscopy, technical photography in transmitted light and raking light, X-rays and infrared reflectography. Detailed information about the buildup and composition of the layers was gathered with the study of cross sections and microsamples, using optical microscopy and chemical analyses. It was shown that Mondrian frequently moved the lines and changed their width up to the very last working phase and, probably, did not use a ruler in the traditional sense to achieve straight lines. In one of the works, Mondrian even employed a pencil, tracing a groove in the wet paint to accentuate straight edges. The black lines consist of multiple paint layers of diluted bone black oil paint, added with small amounts of coloured paint, alternated with thin oil-resin layers, sometimes containing lead white particles. Finally, a thin (pigmented) oil-resin finish was applied on top of the black line.
We present AMUPED (American Useful Plants in Europe Database), a curated and openly accessible dataset documenting archaeobotanical evidence of American plant species recovered from archaeological contexts in Europe from the late 15th to the 20th century. The database currently includes 183 validated records from 141 archaeological sites across 14 European countries, representing 24 taxa from 11 botanical families. Each record contains taxonomic identification, plant part, archaeological context, dating, inferred use, and site metadata. The dataset is complemented by pollen data, domestication sites, and historical documentation of introduced taxa. Data were compiled through a systematic review of published literature and excavation reports and validated by subject specialists to ensure contextual consistency. AMUPED enables analyses of spatial and temporal patterns in plant introductions and the cultural significance of New World taxa in post-1492 Europe, supporting research in archaeobotany, historical ecology, and transatlantic biocultural exchange. This paper presents the rationale, structure, and scope of AMUPED, describes the methods used for data collection and quality control, and highlights key findings. We also discuss current limitations, including geographic and chronological gaps, and outline directions for future expansion, such as the integration of microbotanical data and historical sources. By centralising archaeobotanical records previously scattered across national databases and grey literature, AMUPED provides a foundation for comparative and interdisciplinary research. The database remains open to future contributions from the research community.
Degradation phenomena such as cracking and paint loss have been observed in dark blue paint strokes in Vincent van Gogh's paintings. Analysis of several samples taken from such paint strokes has confirmed that the paint contains Prussian blue pigment, linseed oil and a small amount of beeswax. Research into the chemical and mechanical processes taking place during the ageing of this paint is required to understand the cause behind the degradation phenomena. Therefore, attenuated total reflection Fourier transform infrared spectroscopy was used to study the chemical changes during the artificial ageing of oil paint reconstructions and correlate those changes with visual observations of the paints’ degradation. The influence of different pigments, as well as the pigment volume concentration and the presence of beeswax on the ageing of the reconstructions was investigated. The tested pigments include both soluble and insoluble Prussian blue prepared according to historical 19th-century recipes, modern Prussian blues, and a cobalt blue pigment. Ester hydrolysis was observed during artificial ageing for both cobalt blue and Prussian blue paints, but this effect was much larger for the latter. Additionally, NH3 adsorption and its subsequent conversion to NH4+ were observed in most Prussian blue reconstructions, which is expected to contribute to the increased ester hydrolysis rate in these paints and the formation of free fatty acid efflorescence. The type of Prussian blue pigment was found to influence the capability of NH3 adsorption and the formation of fatty acid efflorescence, as this was not found in all reconstructions.
