Present and future of chromatic reintegrations of wall paintings

Abstract

The chromatic reintegration of wall paintings, also known as inpainting, is a common practice in the con- servation and restoration of Cultural Heritage (CH). The main objective of the treatment is to make the narrative content of paintings with lacunae (i.e. missing paint) more artistically and iconographically leg- ible. Very few scientific studies have addressed the suitability and durability of the materials used in this kind of procedure, despite the importance of this question. Even less information is available regarding wall paintings, which are more susceptible to deterioration than other artworks due to their partial or complete exposure to extreme environmental agents (relative humidity, ultraviolet radiation, etc.). To this end, we have carried out a review of this subject bearing in mind that chromatic reintegrations should also comply with the principles of recognizability, reversibility and compatibility established in the mid- 20th century. In this review, the influence and behaviour of pigments, binders (e.g. gum Arabic, mastic or urea-aldehyde resin, etc.) and protectors are discussed, together with the latest modern restoration practices based on ‘mineral painting’, in which silicates are used as binders. Overall, this field of study deserves more attention as the materials being used have not yet been thoroughly evaluated. These ma- terials should be further assessed in terms of their visual and chemical-mineralogical compatibility with the original painting, their durability and stability in the long term under adverse weather conditions, and their reversibility.