Blacken stainless, safe for skin and long-lasting

[RockTheBilly]

Hello! I am an independent jewelry designer working mostly with laser cut stainless steel (brush finished). I am looking for a way to blacken the jewelry myself in my studio for higher contrast against paler skin types. I need to be able to blacken around 800 pieces per month, so I would prefer to avoid brush-on techniques. Also, I'm really looking for something I can do at room temperature.

I wanted to try the stainless steel blackener but was told the finish may rub off and it might be unsafe for continuous wear against the skin. Does anyone know a method I can use that is permanent (or, very long lasting) and will not be harmful to your skin?

I was also researching the Black Krome kit a bit, but I'm not really sure how it works or if it's realistic for me to try. I know very, very little about metal finishing.

I appreciate your time spent reading my inquiry and I thank you in advance for any suggestions you can offer!

[Brintiff]

I have no idea if the stainless blackening is skin safe for long periods of time but I can tell you black chrome would not be a good finish for jewelry, it's much to soft.