Inlaying the laser engraving with colour
As previously mentioned some stones do not produce good laser engraving results. By subsequently filling the engravings with acrylic paint (or similar type of paint), you can achieve a high-contrast result. To do this, mask the engraving surface with an application tape, and engrave your desired graphic. Then take acrylic paint and a bristle brush, and dab at the engraved areas with paint. Ensure that the paint has dried and peel off the tape, washing off the remaining, finer tape residue with water.
Better filling results are achieved on smoother or more finely polished stones. Porous or rough surfaces may cause the edges of your artwork to fray, thus not revealing a good contrast.