Mezzotinta on stone (ossi di seppia, manière noire ) is a noble lithographic negative technique. The lithographic stone is covered with Syrian asphalt diluted with turpentine. This is a bitumen found in natural deposits on the shores of the Dead Sea. Syrian asphalt was also used as a light sensitive substance in the first photograph taken by Joseph-Nicéphore Niépce. The technique is characterised by the velvet black of the background, obtained in the process of graining the stone. The image created this way is similar to the traditional intaglio mezzotint on metal plates, and the most delicate, silvery tones are achieved through scraping the surface with the skeleton of a cuttlefish called ossa sepia . The point of departure for the Rays series were radiographs – photographic images obtained through the operation of X rays, which are detrimental to health (around 99% of the radiation is absorbed by the body).