Yuri Koval is a PhD student at the State University of Lomonosov in Moscow. His professional interests are linked with reconstruction of chert stone processing in High and Late Palaeolithic. Since 1994, he works in the area of experimental archaeology. He represents the Peterborough School of chert processing. In April, 2008, he was on scholarship in Kraków under scientific supervision of PhD Krzysztof Sobczyk (Institute of Archaeology, Jagiellonian University). He proceeded a series of presentations for the scholars and students of the IAUJ that included processing of chert according to the practice of Middle, High and Late Palaeolithic. He used Polish material – Jurassic chert, brown chert, striped chert. The material was donated by Mr Cezary Łutowicz from Sandomierz – www.krzemien-sandomierz.pl).