International symposium on the technical examination of old masters drawings was held in London (May, 2010.). The host of the meeting was the Department of Conservation and Scientific Research of the British Museum with the support from Andrew W. Mellon Foundation from the United States. There I have presented my poster presentation Through the"divine science"of Leonardo's Mona Lisa. This research was based on comprehensive study of Leonardo's painting technique, formed according to the published results of noninvasive studies of the restoration centre at the Louvre. Leonardo's painting technique was also the topic of my diploma thesis at the Conservation-restoration department in Academy of Arts in Split 2007.