Full-field NDT methods for investigation of paintings on poplar

The diagnostic of artworks represents a topic of high interest and at the same time a critical task. The development of effective tools based on advanced technologies for investigating and monitoring health-state of item of interest for cultural heritage is essential to assuring their preservation and restoration. In fact, detecting and preventing the formation of damages or assessing them for an accurate pre-restoration analysis are the main objectives of non-destructive investigation. In this study the combined use of Electronic Speckle Pattern Interferometry and Pulse Thermography Analysis, as complementary tools for cultural heritage artifacts diagnostics have been employed on poplar panels painted reproducing original painting methods adopted during the 16th and 17th centuries. Both techniques are full field, contactless, non-invasive and can provide relevant information about state of conservation. The concurrent investigations, allow to expand understanding the results of each individual technique, from which, in many cases, no exclusive assumption is possible. The applications include detection of detachments, micro-cracks, inclusions, and hidden damages. It is also possible the real time monitoring of the behaviour of the object according to the environment thermo-hygrometric changes. The porpoise of this work is to optimize the parameters of such NDT methods on the samples that were specially made by reproducing in high fidelity the structural properties and materials of the artwork. Results show that the employed diagnostic protocols, by speckle interferometry and pulse thermography, are a powerful tool in assessing the pre-restoration health-state and suitable for in situ analysis of wood artworks. Examples of analysis on different artworks are shown.