Hey Sue,
Hope your etching experimentation is going well.
I wanted to add my 2 cents to the resist discussion. You don't need to only use the Staz-on inks; all sorts of resists work. I especially enjoy drawing designs directly on my metal with permanent markers.
Plenty of folks use Sharpies, but I don't like the quality of resist I get from those. When I was first learning etching, my teacher turned us on to Staedtler Lumocolor pens. They're super-fine, they last nearly forever, and they're available at office or art supply stores. Plus they give a nice solid resist line with ferric-chloride etchant.
No wonder they're my absolute go-to favorite, huh? Just make sure you get the PERMANENT kind, not the wipe-off variety. Oh, and red seems to work the best - go figure.
Best of luck etching!
~Addie~