... board, gold, silver,copper, iron, stannum etc, it ' s a new technology product that you make your own choice ... No smell, No dust, and you can use it anywhere. It suit for all engraving picture industries. 2, Work ... any shape of plane bend, slice and arc. It's not only same result as the laser engraving products, ... column and so on. And on the basis of it, it can also color them with gold, red, yellow, ...