1. Conservation Center; Institute for the Protection of the Cultural Heritage of Slovenia; Poljanska 40 1000 Ljubljana Slovenia
2. Museum Conservation Institute; Smithsonian Institution; 4210 Silver Hill Rd. Suitland MD 20746 USA
3. Department of Analytical Chemistry, Faculty of Science and Technology; University of the Basque Country (UPV/EHU); P.O. Box 644 48080 Bilbao Spain
4. Chair of Territory, Landscape and Heritage; University of the Basque Country (UPV/EHU); P.O. Box 450 01080 Vitoria-Gasteiz Spain