There is a stencil material that you type onto with a typewriter then use for electroetchI'm not sure we're talking about the same thing but you mean the stencils made on vinyl printers?
I use them all the time on Ak selector marks.
There's a guy on eBay and gun broker that goes by thors hammer that I think dies custom ones.
A small electronics charger with alligator clips added to the wire and a heavy salt water solution.
Cotton makeup type pad.
Thanks for sharing that. That is worlds better looking than my stamping jobs!Did this earlier today. Economy marking kit from Lectroetch.