GB'S PARIS is an independent firm specializing in the expertise, authentication, and advisory of Pre-Columbian art and antiquities from the Americas.
Founded by Guillaume J.A. Bresso, PhD, the firm unites academic research, practical mastery of ancient techniques, and advanced scientific methods. We support private collectors, institutions, auction houses, and insurance companies in the study, safeguarding, and enhancement of their cultural assets.
The Founder
Guillaume J.A. Bresso is an art historian and specialist in Mesoamerican civilizations.
His early field experience on major archaeological sites — including Baalbek and Petra — shaped a keen sensitivity to the physical presence of ancient objects. In 2008, he co-founded Ateliers Leonis, where he acquired a rare hands-on mastery of ancient reproduction techniques, from modelling and firing to slips and patinas.
His research centers on Mesoamerican writing systems, iconography, and cosmology, with a particular focus on Maya and Mixtec cultures. He is a partner of the UNESCO-UNEVOC network.
Our Methodology
Authentication rests on a systematic, multidisciplinary approach that integrates several complementary perspectives:
- Deep iconographic and stylistic analysis
- Practical understanding of ancient manufacturing techniques, developed through experimental archaeology
- Scientific testing, including thermoluminescence (TL), optically stimulated luminescence (OSL), and mass spectrometry techniques
- Examination of patina, wear patterns, and material composition
- Provenance research and anthracological study
Conclusions are drawn from the rigorous synthesis of stylistic, technical, and scientific evidence.
Ethics and Compliance
GB'S PARIS operates with the highest standards of independence, impartiality, and confidentiality. The firm works in full accordance with:
- The 1970 UNESCO Convention
- Regulation (EU) 2019/880 on the import of cultural goods
- French regulations on the fight against illicit trafficking
Every assessment is designed to protect collections while contributing to the broader preservation of cultural heritage.
Discover Our Expertise
Contact us to discuss how we can assist you with your collection or specific object.
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