Yeah, RNB seems to be a bit trickier to apply nicely on a smooth surface. I would give it a coat of flat black spray paint first if you want it to have an antique look. Then when you apply the RNB, you can either use a tiny little bit on your finger or use a paintbrush. With a brush, dip it in a little RNB then dab it on some paper, so there isn't much left on the brush, then kinda dab it on the gun. RNB can be cleaned off with paint thinners, but that will also remove your black spray paint as well. I wish at this point I could find something that would take off the RNB but leave the black.... It takes a bit of experimenting to get the effect you want, so, maybe try it on something else first. Of course if it all goes terribly wrong, just spray it all black and start again. Oh, yeah, another thing I noticed is that it seems almost impossible to do one colour and then another on top because the top colour seems to soften the bottom one and they just mix together. Anyways, hope that helped a little. I'm happy to try and answer any other questions if I can. Good luck!
That is a great wealth of hands-on knowledge. I sincerely appreciate it. With washes you can sometimes use thinner based paint over water-based acrylics without damaging the undercoating (and vice versa). I am wondering if that might work for the RNB.
I will try experimenting on some random plastic first - spray it black, etc.
Great detailed tips on the amount on the brush and applying more than one color. I will definitely utilize your generous offer of additional advice when I try it out. Thanks again!
Mmm good idea with using acrylics, I'll have to try it. What I would really like to be able to do is apply black over the RNB and then wipe off to reveal the highlights. That is the way I work when using actual metal, so that's how my mind still wants to do it. Anyways, I'd love it if you could keep me posted what works for you... Also, here's a little tutorial I threw together where I RNB a box to give it this effect. [link]