For those not inclined to watch the video: take a brass plate, spray paint a side, use a laser to burn off part of the lacquer leaving behind some as an etch resist. Place the brass in an acid that eats away the exposed brass!
Thank you for the reply @Brendon_Hatcher and for the page update.
I think this falls into the unlisted section. 1 is not applicable as lacquer isn’t specifically a laser product. I tired looking on 2 and 3 but can’t find anything exactly like this.
So I’m asking for thoughts and permission to experiment. Here is the data sheet for the lacquer I’d use (the one from the YouTube video). It’s acrylic based and as far as I can tell there is no cross over with what the Trotec and the tool page say not to use on a laser cutter.