Ideas

List of experimental things to try

Cermark

Cermark appears to be a type of paint that once applied to metal will cause it to be etched once a laser is fired at it. The only down side is that it appears to be fairly expensive

One approach might be Isopropyl and Plaster

• http://hackaday.com/2014/12/25/laser-etch-stainless-with-only-plaster-alcohol/
• http://hackaday.com/2010/08/17/negative-laser-etching/

Kapton tape

One thing mentioned in this article is putting kapton tape over copper for it to interact with the laser

• http://hackaday.com/2014/12/25/laser-etch-stainless-with-only-plaster-alcohol/

Conductive Paint

One idea might be to experiment with conductive paint and copper plating on a laser friendly board