Od 2025 roku nastąpiła zmiana tytułu czasopisma i numeru ISSN na: npj Heritage Science ISSN 3059-3220 (online) W PBN nie nastąpiła aktualizacja tytułu

This paper presents a comparative analysis of the durability of six commercial and modified retouching paints containing ultramarine blue or cadmium yellow pigments. The paints were subjected to high temperatures, light, and naturally aged for 4 years. The analysis focuses on evaluating chemical and physical changes leading to alterations in colour and wettability. The controlled museum environment does not entirely eliminate the detrimental impact of these factors, therefore the restoration procedure must be undertaken. The conservation of 18th-century paintings (Czartoryski Princes collection, National Museum in Kraków) has contributed to the study of changes in retouching media and the selection of the best ones. An analysis of commercial paints with similar compositions revealed notable differences in colour stability and mechanical properties. In the case of watercolors containing Arabic gum, the primary degradation process was the organic component evaporation. Conversely, for cycloketones and aldehydes resin-based paints, oxidation was the predominant process.