The subject of counterfeit artworks has long been taboo, but today an increasing number of museums are opening up their collections to transparent assessments, sharing research findings and deattributing works when necessary. Over the past ten years, the Museum Ludwig, together with international scholars, has been systematically examining its collection of Russian avant-garde paintings that were acquired by Peter and Irene Ludwig and donated to the museum in 2011. Based on twenty-four examples, the research presented here not only reveals the detailed process involved in confirming the authenticity or inauthenticity of a painting but also offers valuable insight into the working methods of the artists of the Russian avant-garde. Text: Konstantin Akinsha, Friederike Gräfin von Brühl & Ruth Lecher, Meike Deilmann, Yilmaz Dziewior, Rita Kersting, Maria Kokkori, Petra Mandtweiterlesen