After my not so chic, Revlon Chic mani a few days ago, I needed to do something to dress it up a bit. I sponged China Glaze Liquid Leather over the top of it. I don't know that I would technically call this a gradient, because there's not really a transition from one color to the next. It almost looks like a sponged Ruffian. Either way, I really like it.
You know what I don't like? The mess sponging makes of your fingers. And black is hard to clean up if you skin isn't pristine. This is my right hand and it's always a little worse for wear than my left. It works harder and sometimes it shows. The black that got on my skin was really hard to clean up.
I would do this again. Maybe with a little glitter and sparkle too.