‘The true Colours’ of Chalcolithic Cucuteni–Trypillia Pottery: Experimental and multi-analytical approaches to painting technology

The Chalcolithic Cucuteni–Trypillia culture (c. 5000–3500 BCE) is renowned for its trichrome mineral-painted pottery. While pigment compositions are well documented, the specific chaînes opératoires regarding paint preparation and application sequences remain debated. This study addresses this gap through a three-year systematic experimental programme (over 50 scenarios) integrated with a comparative multi-analytical approach. Experimental samples and 13 original Cucuteni sherds were analysed under identical laboratory conditions using Optical Microscopy (OM), SEM-EDX, and μ-FTIR. The results indicate that, under the tested firing conditions, organic binders did not produce stable coatings comparable to the archaeological material, whereas a levigated clay-slip vehicle provided a more effective aluminosilicate matrix for pigment fixation. Microscopic analysis supports the existence of a technological dualism in the preparation of white grounds, involving both true calcium-rich slips and mechanically induced ‘self-slips’ or scumming, probably enhanced by burnishing at the leather-hard stage. Macro- and microscopic evidence is also consistent with operational sequences in which vessels were often burnished after painting, embedding the pigments before a single firing. Conversely, the tested post-firing painting scenarios sealed with organic layers received limited support, as they failed to reproduce the long-term stability and surface characteristics observed on the archaeological sherds. Ultimately, this study highlights that the exceptional quality of Cucuteni–Trypillia pottery relied not only on specific mineral recipes but equally on the artisans’ masterly control over drying kinetics and surface mechanical manipulation.