Hi, I was wondering if any of you know how to get a nice, uniform black finish on bronze?

I tried liver of sulfur, and while I managed to get black colour, it was very fragile and flaking of at any opportunity. Then I sort of depletion gilded the bronze, so I'd have copper at the surface, but LOS still wouldn't work. It was a freshly opened patina gel, by the way, so that's not where the problem is. Everything was clean, and I tried different solutions, thinking that maybe what I was using was too diluted, or too strong, but nothing would work . I asked this question on facebook, in two jewellery groups I'm in, but I really didn't get any useful tips (apart from suggestion to try depletion gilding the bronze).

Is there any patina solution that would create durable, smooth black finish on bronze? This can't be anything you need to be vat registered to buy, because I'm not, and I also live in the middle of nowhere in Northern Ireland, so I can't just go to the physical store at cooksongold or anywhere else.

While looking on google, I found someone mentioning they managed to get dark/black finish on bronze by putting it in lye solution for a few days, but didn't really provide much info about how they did it. Did anyone here ever did this or heard about this? Because at this point I'd be willing to try that, but if this works, I'd have to dunk the piece in vinegar or other acid after rinsing, to neutralise the lye, and I'm not sure this wouldn't wreck my finish. Not to mention I'm not even sure how durable the finish would be... if it works at all.

In case you need to know what I'm trying to do: I have two armour rings, each one with simple engravings on it, and I want to get the rings all black, in and out, and then run the engraving bit through the engravings again, to expose bronze only there. So sort of opposite of what people usually do. It's so annoying, I'm rather proud of them, but can't get them finished :/

Does anyone have any ideas?