My boss and I are experimenting with several different ways to micro machine .01" and .005" stainless steel. When I look up how it's done professionally, I see an overwhelming majority of companies use photochemical etching (acid etching). I have also seen electrochemical etching as an option, but not as a "precision" method. So far, both methods have achieved sub-millimeter precision and electroetching currently takes a slight lead over photochem, but neither have achieved the incredible accuracy that I've seen online that appears to have resolution finer than the human eye can distinguish.
Electrochem etching has also proven to be much simpler and safer since we don't have to be involved with potentially dangerous chemicals. My suspicion was that acid etching would be more precise since it is so widely used, but our results are not supporting that hypothesis. I am wondering what advantages does acid etching have over electroetching that makes it so much more popular? I'm curious to know more so we can further refine our etching process.