[5] Engraving on bone and ivory is an important approach for that Artwork with the Upper Paleolithic, and larger engraved petroglyphs on rocks are identified from quite a few prehistoric periods and cultures worldwide. Laser engravers using a 20W Infrared (IR) diode or 20w+ C02 lasers can engrave clear https://peterz123vvi5.wikicommunications.com/user