ABSTRACT
Gilding is an important object of study in the context of heritage restoration and conservation. Gold leaves used for gilding have colors or shades according to the content of the various metals such as gold, silver, copper and others. However, time and possible alterations can modify the original shades, which makes it difficult to find a gold leaf equivalent to the original one. In order to build a model allowing us to classify gildings according to their composition, Laser Induced Breakdown Spectroscopy (LIBS) has been used. Particular gold (Au), silver (Ag), copper (Cu) and zinc (Zn) rays were studied. A Principal Component Analysis (PCA) has been performed to develop a classification model from gilding standards with known content. The resulted model has been applied on samples to identify original and restored gildings. Thereby, this approach using LIBS, could be performed on site to help restorers and gilders in their work.
