Guillaume J.A. Bresso

His expertise is grounded in prolonged fieldwork in Central and West Africa and Papua New Guinea, alongside academic training in anthropology and art history.

In 2008, he co-founded the Leonis Workshops, acquiring practical mastery of traditional carving and surface treatment techniques.

He performs authentication and valuation through a structured methodology combining stylistic and iconographic analysis, detailed technical examination of materials, tool marks, patina development, and resin layers, together with provenance research.

Particular attention is paid to potential discrepancies between apparent age, stylistic attribution, and material evidence — a key factor in distinguishing authentic works from later pieces or forgeries.

Scientific analyses (thermoluminescence, mass spectrometry, anthracology) are carried out when relevant, through long-standing partnerships with specialized laboratories.