16.4: Principles Governing Conservation Practice

Behind much conservation thinking lies the concept of the biography of an object (Appadurai 1986; Gosden and Marshall 1999). Each object may have gone through many changes in its so-called ‘life’, each of which may have left some kind of trace. These traces may be the results of material changes, such as corrosion of metals, or caused through human agency, such as the wear marks induced by use. Thus objects contain a range of material and conceptual evidence and can be seen as embodied technical and social history, or documents waiting to be read. Much of this information remains latent until elucidated during conservation.

A key conservation principle is that understanding objects is an essential first step in reaching conservation decisions. Conservators examine (‘read’) objects in great detail. Their assessment and diagnosis of the objects’ conservation needs depends on: investigation of material(s) (thus of technologies); condition (thus of deterioration, signs of use, modification, repair or recycling); significance (thus of history, and of meaning assigned to these objects by different past and present individuals and groups); and future use (thus of potential to make new or further meanings). This assessment must involve communication and collaboration with other scholars and interest groups, particularly when developing an understanding of significance. It will also involve laboratory investigation such as microscopic examination and materials testing which may reveal a range of information not accessible through normal visual examination.

Another of the principles of conservation is that procedures should not affect the identity — the materials or the various possible meanings — of the object. In the past this was coupled with the principle of reversibility: that any changes induced by conservation could be reversed if necessary, thus supporting the aim of minimising change to the object. However, the principle of reversibility now remains only as an attractive idea, since it is widely acknowledged to be impossible to put into practice effectively (Appelbaum 1987; Muñoz Viñas 2005: 183–188).

The principle of minimum intervention (which to some extent replaces reversibility) acknowledges that conservation inevitably changes either the material (e.g. through cleaning) or the perception of an object (e.g. through analysis or restoration processes) or possibly both (Muñoz Viñas 2009). So the aim is to minimise change by doing as little as possible to the object provided it is enough to achieve a satisfactory conservation result. The intention is that this approach will not only limit change to the materials and/or distortion of the meaning(s), but that it should allow for further investigation in the future, and if necessary, future retreatment. To apply this principle effectively it is essential to understand the object well enough to be confident about where (and where not) to intervene with conservation treatment.