I have searched and searched but I cannot find a simple explanation of how electro etching stencils actually work (like the kind made by the famous 'Ernie'). I see people using fingernail polish as a resist, ironing photocopied designs onto steel, using electrical tape. I have all the parts to build my own electro etcher and I think I can get it wired up properly, but I just don't understand the whole stencil thing.
I saw a DIY for simply ironing a reverse image photocopy to the blade and I imagine the toner acts as a sort of resist, but as far as I can tell, the type of stencils Ernie Gropnik(?) sells are on a transparent film that you tape to the blade and then hold the solution dampened sponge on it. How does the electricity get through the membrane and into the blade? What am I not understanding here?
I saw a DIY for simply ironing a reverse image photocopy to the blade and I imagine the toner acts as a sort of resist, but as far as I can tell, the type of stencils Ernie Gropnik(?) sells are on a transparent film that you tape to the blade and then hold the solution dampened sponge on it. How does the electricity get through the membrane and into the blade? What am I not understanding here?