Pretty pleased with this. It took 3 1/2 hours to get it this deep but the
etch itself is nice and clean with the ferric nitrate solution. The
line is just permanent marker with tape around the edge, you can see
where the tape bubbled in the bottom left corner. So, I think this
solution is going to be fine to proceed.
Been talking about doing some work with David's (link) illustrations for a
while now. Stuart guided me through putting a photo resist on silver.
I'm looking forward to etching this.