Nanoindentation of Historic and Artists’ Paints

The micromechanical analysis of composite materials has become indispensable in the field of material science and for industrial applications, where small sample sizes predominate. In recent years, nanoindentation has been more readily utilized within the cultural heritage field, producing invaluable insight in the properties of artists’ materials. To take full advantage of the technique, however, issues related to the scale of the analysis need to be addressed. These include understanding the influence of sample preparation and material heterogeneity on the obtained results as well as establishing correlations between micro/nano-scale and macro-scale mechanical parameters. Moreover, the nanoindentation tests of time-dependent paints and adhesives can be difficult to interpret and thus require the development of unique measuring protocols. This review discusses nanoindentation studies of artists’ paints carried out over the last two decades. Analysis of presented experimental and theoretical works focuses on comprehending limitations of the technique and developing strategies to overcome them. We demonstrate how consistent and reliable measurements can be performed when experimental protocols consider the effects of geometry, roughness, and time-dependent properties of paint, as well as the compliance of the measuring system. Development of measurement protocols accounting for specific properties of historic and artists’ paints opens up the prospect of more routine application of nanoindentation in the field of cultural heritage.