laser engraving and etching

Consumer and prosumer laser cutters can fall short. Two areas where they usually fail is in deep engraving wood without charring and engraving metals, especially stainless steel.
I solved the wood problem, and came up with an elegant solution for precise, affordable deep etching of metals. Basically, I use the laser to cut a resist out of a layer of primer, then etch the metal using easily using a simple salt solution and low voltage from a wall wart DC phone charger.