Saw this on a Makezine weekly tip. Might be something interesting to try. I think the keys are that the surface has to be sealed first, before engraving, and shallow engraving depths. #K40ShopTips
Tip for coloring engraving - YouTube
Excellent technique …
I don’t know how the laser will react to a slight finish coat of lacquer or urethane. One can apply a light coat of finish, then engrave and then apply the dye. This will help keep the dye from bleeding and result in crisp lines on the outline.
In pyrography the burned interface between the smooth area and the engraved area seals the grain with the heat, I am guessing the laser does the same.
@donkjr I engrave through poly and lacquer all the time without any issues.