My ole’ lab buddy Thantik has been trying to etch PCB’s lately, and today he did something none of us even thought of: using the laser cutter to etch a PCB.

When we realized that our 40W laser couldn’t etch the copper itself off we were super bummed. We found out about this spray-on compound called Cermark that is supposed to be able to mark copper. We thought we could use that to create a mask, etch the copper out with acid, and sandpaper the cermark off. But it was around $70 a bottle.

Thantik covered a copper-clad board with simple, cheap satin black spray paint, let it dry, etching the paint off the copper with the laser cutter, and etched it with ferric chloride, then took off the paint with acetone.

This is what he came up with: