There are several projects around the world to develop training programmes and databases of stolen goods to be used by law enforcement agencies within the field of cultural heritage conservation. However, the use of these databases has not been spread to a global level because the laws that protect cultural items vary widely by country. The development of international databases for endangered or stolen art has already been initiated by, for example, the Getty Information Institute with international governments and other bodies such as Interpol (Object ID), and the International Congress of Museums ICOM (Red List). However, many museum archiving systems are not standardised, so that linking them, with or without fingerprints, is difficult.
The FING-ART-PRINT project was supported by the European Commission Sixth Framework Programme (FP6), Priority 8.1.B.3.6 on a topic of protection of cultural heritage and conservation strategies. It was coordinated by the Rijksdienst voor het Cultureel Erfgoed, based in the Netherlands.
The innovative product that has been developed within the project is a system for scanning and “finger printing” cultural or art objects, so they can be traced and identified while on loan or transport. A commercial confocal microscope has been adapted specifically for this system to take fingerprints, and to work on a flexible robot system. This fingerprint consists of two measurements taken from a selected area of the surface of the object, the micro-roughness using a “profilometer”, and the reflectance spectra (colour) using a multi-spectral camera. The technique makes use of the fact that various height/depth levels of an uneven surface can be observed under the light microscope by focusing with the objective lens, that is, by moving the lens up and down. This is essentially a depth analysis. A confocal white light “profilometer” analyses the entire visible area at once by scanning ‘through’ all depth levels, thus producing a set of height/depth contours. These contours are combined and can be presented as false colour topographic ‘maps’ of the surface, and can be saved as .jpg files. The roughness data is saved in the system as an ASCII file. A user-friendly software tool has been developed by the University of Southampton, so that users without any technical training are able to use the system (including museum staff, historian, collection manager, conservator, etc.). Furthermore, it is a portable system that can be used on site in events such as archaeological excavations, or temporary museum exhibits. A webcam is used to record the exact location of the 1cm2 area that was scanned to produce the fingerprint, so that it can be relocated and rescanned in the future.
This technique has been successfully demonstrated to over 70 international conservators and other cultural heritage personnel using the prototype during two workshops. Three sets of
case studies have been also carried out over the duration of the project. Nine museums, one art gallery, two cultural heritage institutes with their own collections (ICN and OADC), several private conservators, and three law enforcement units participated, providing over 35 objects for roughness fingerprint measurements. These included paintings with and without varnish, books and lithographs, cast metal objects, corroded metal objects, archaeological and historic ceramics, with and without glazes, and wood. However, it reaches a level 8 in the TRL scale because is not yet commercialised.
Given the non-contact method of taking the fingerprints of cultural and art objects, the final product could be of interest to private investors, museums, the archaeology community, EuroPol, UNESCO, and public administrations.