HART (Historically Accurate Reconstruction Techniques) is a three-part methodology for researching historical materials and techniques used in the production of art by making reconstructions. The HART approach can cover a wide range of cultural artefacts including illuminated manuscripts, oil paintings, painted statuary, stained glass, metals ceramics and works of art on paper. 

Part one of HART research involves the study of historic documents contemporary with the area of interest (such as 13th century pigment recipes and formulations as well as instructions for their production or application). Part two includes chemical analyses from actual art works, for example pigment and binder identification to establish the materials present, and Part three involves reconstructing the materials and production processes. An essential feature of the HART method is that reconstructions are based on sourcing historically appropriate materials. 

There are a number of different objectives in re-creating old recipes: to discover what the materials were like to prepare and apply (to gain insight into the artist or maker’s experience); to evaluate their effectiveness or performance (determine the cause of subsequent defects for example); and to create a set of reference samples. Reference samples can be used to explore the chemistry of the materials, including their chemical interactions over time, in relation to actual examples from art works; and to understand the physical-mechanical properties of historic materials by replicating them as far as possible. These highly characterised reference samples are essential for calibrating analytical instrumentation and for well-designed protocols for investigation into artists’ materials and their history of use. These reference samples are also essential for evaluating or anticipating the impact of conservation treatments on works of art.

By setting out to explore historical materials, one is confronted by how modern materials differ. For example, it is important to know that modern pigment particles can be coated with silicates or vegetable products to enhance their dispersion in the binder (e.g. oil). These coatings can interrupt pigment-binder interactions chemically, and can also result in significantly different distribution of materials within a paint layer, such that paint made with these modern materials will not reflect the appearance or behaviour of historic paints. 

A further benefit of HART research is that the understanding of the preparation of modern materials versus those in the past provides an entry point and an approach to thinking about the material world and how it has changed over time.