Robin found some copper flashing at the hardware store. Hell yeah I’ll etch it.
The glint is good, but it comes with a traveling vertical line that reflects the light source. I need to see if I can treat the surface to avoid that before etching. By happenstance I found that a rectilinear light source (office neon) perpendicular to the etching works better than a single light source pointed at it. It covers more vertical angles of viewing while not diffusing the horizontal effect. Running it parallel, much like a diffuse light source, ruins everything. I should draw how this stuff works a bit.