Thanks for sharing - the tuts I saw before used large batteries and talked about containers of fluids for submersing the materials in - yours seems so much more compact and easier to do. I also have seen Sharpie as a resist, and that is what I use to etch with acid, so I may give this a go and try it with the Sharpie. Thanks again!
Ohhhhh - or would you consider 4x4 chunkies? I like the chunky canvases - the ones that are 4x4x1 inches. Shipping would be pricier - but then the sides can be decorated, and those who want can also have the option of decorating the back/inside too!