In addition, the analysis was carried out applying methods of engraving. Specialists convinced that obsidian, silicon and bronze tools (taken for the experiment in the museum) are not left on the surface of the stones of any significant traces and steel tools can barely scratch the surface. As a result of experiments, experts came to the conclusion that the same tracks, similar to the technique of images in the Ica stones, leaves cutter drill. This, by the way, was used by skeptics as proof that the Ica stones - a product of modern counterfeiters. However, the assumption that manufacturers stones with similar technologies, it is not too bold a comparison with the main motifs of images on the Ica stones.