General recommendation on sculpturing new material when restoration the Angkor Temples
The replacement of sculptured material is often necessary for reasons of structural stability or to lacunae, or perhaps to achieve an overall consistency in a particular structure. However, the group of experts for conservation wishes to recall the following points in terms of intervention on monuments as defined by international charters and particularly the Nara Document on Authenticity and the Angkor Charter:
1. The conservation of the original material and its restoration must always be preferred to any replacement, in order to preserve the authenticity of the work as much as possible.
2. The possible replacement of a sculpted item must be based on historical, documentary and analogue research and must be thoroughly documented and justified.
3. Once in place, the new structure to be sculpted must be perfectly perceptible to a discerning eye.
4. a) If no information exists on the patterns of the missing decorations, these will be reproduced only in their geometry or general shapes.
b) If the motifs to be reproduced are known, the operator will be satisfied with a size approach without completely restoring the décor so that the overall vision of the work is preserved and that there is no subjective interpretation later.
c) If a new stone must be inserted in the immediate vicinity of a very altered or eroded ancient stone, a problem of esthetics arises and the solution will consider the general harmony of the area to be treated and may include giving the new stone the appearance of wear.
d) With those principles of legibility of the restoration in mind, it must be said that any restoration must be analyzed case by case, in particular according to the significance of the monument or the proposed interventions and must be the subject of a collegial approach which alone can allow to stray somewhat from these principles
e) That approach in principle does not exclude the use of a more advanced restoration of a sculptured piece if the material to be sculpted is isolated, one-off, displayed as a testimony, or is small in size and if there is a need for overall harmony.
f) In this case, various means can make it possible to address the same concern for legibility such as the dating of the work, artificial wear.
5. Finally, it should be remembered that a restoration, in addition to its authentic character, must be esthetic, harmonious and pleasant to see for all visitors and without misrepresentation from the standpoint of the discerning visitor. This may therefore justify the use of a light patina on new stones so that their general shade harmonizes better with the old stones.