Modern technology in artwork conservation: a laser-based approach for process control and evaluation

The present work includes a laser-based methodology for the cleaning of artworks, with emphasis on the preservation of their structural integrity and identity. Modern laser-based techniques and instrumentation offer new tools in the field of artwork and antiquities conservation, aiming to alleviate the traditionally applied methods from existing weaknesses. Although in several cases the use of lasers may give rise to superior results. there are still problems to be resolved in relation to the optimization of procedures for safeguarding from potential damage. Furthermore. several operational parameters have to be simultaneously controlled and the long-term effects induced by laser irradiation must be assessed in detail before a full exploitation of the new methods is established. The control of material removal during laser cleaning is achieved by using laser-induced breakdown spectroscopy (LIBS). This control relies on the collection of spectroscopic data by LIES, which correspond to the in-depth compositional profile of the artifact. This technique may be combined with structural analysis by holographic interferometry. The latter is important for assessing structural changes, which may be induced during laser ablation. Selected examples of this type of applications in a carefully considered methodology are presented. (C) 2001 Elsevier Science Ltd. All rights reserved.