Friday, May 6, 2011

Non-Toxic Etching Update

I just received an e-mail from someone who read my non-toxic etching post from last year. I realized after rereading the post that the information there needs to be updated. It was written after just one test with a copper sulfate solution and I erroneously reported that the etching time for zinc in copper sulfate was the same as with nitric acid. This is definitely not the case. The copper sulfate solution etches zinc much, much faster and the bite is much harsher than etching with nitric acid.

I also have not had much luck aquatinting with copper sulfate since I work with subtle variations in tone. And since the bite is much harsher and quicker, it's very difficult to get subtle or delicate effects. Though if someone has had better results with this I'd love to know about it.

If you include thick, bold lines in your etchings, I would say that copper sulfate will give you that more quickly than nitric acid. But I need to do more experiments with copper sulfate before I can give advice about how to create delicate work. So far my attempts at this have been unsuccessful.

If you have had a lot of experience with copper sulfate and zinc, I would very much appreciate hearing from you about your experience.