Glen, my understand on metal etching is that it's for foils. In the pic below, same artwork, the 1/4 inch Al is waterjet cut as a template to lay on a shirt and spray bleach over it.
The T-Rex Cu foils were something we did 2 years ago and glued them to the shirt with carpet glue. LABOR INTENSIVE. Sad part was stores were worried about returns with the foil crinkling in the wash, which only made them look better IMHO. Hitting these with a torch here and there made them truly special.
For our in-store signs, we'd be looking at 1/8 inch Al sheet stock.
Local means machine shop in NH, though if the etching would work, that would be here in MA where we had the foils done.
