Identifying Vilhelm Hammershøi’s career phases: a data-driven technical and art historical investigation of painting materials and themes.

This study aimed to combine art historical research, material analysis and computational techniques to identify distinct phases in the Danish artist Vilhelm Hammershøi’s career, revealing patterns in his choice of motifs and painting materials, particularly canvases and ground layers, across a large selection of his works. A relational database was developed to organise large amounts of observations and results from the examination of nearly 140 canvas paintings by the artist, including art historical information, structural characteristics of canvases from X‑ray imaging, and chemical properties of preparatory layers from scanning electron microscopy coupled with energy dispersive X‑ray spectroscopy. A data mining technique based on self-organising maps and hierarchical cluster analysis identified distinct categories of canvas weaves and ground layers, each with a unique structure and pigment composition. At the same time, network analysis based on art historical research, including aspects such as the dates of creation, origins and motifs of the paintings, revealed inter-painting connections that highlight specific groups of works in Hammershøi’s oeuvre. The integration of these approaches uncovered significant developments in the artist’s material and stylistic choices, defining three career phases with key transitions around 1890 and 1900, likely reflecting influences from his travels in France, Italy and the UK. These findings address a critical gap in art historical research, as no prior studies have systematically examined Hammershøi’s artistic evolution through such a comprehensive technical approach. The study also has practical implications for conservation, offering insights into material properties that can aid in assessing the condition of the artist’s paintings. In conclusion, this research establishes a valuable foundation for understanding developments in Hammershøi’s method, contributing to both art history and preservation practices.