On steel or anything else most use the rustoleum. On brass or nickle silver you can also use some cold blue solution. The "Super Blue" from Birchwood Casey is good, their "Perma Blue" doesn't work as well, not black enough. Brownells "Oxpo" blue is great also, that's what Jim Small uses and you can see it in many of his engraving pics on some knives and stuff he's done. It won't work as well on steel though, again not enough penetration and not black enough.
If you use rustoleum, wipe the excess off with newsprint or printer paper or some other slick paper, don't use any rag or paper towel as it will lift the ink or paint out of the cuts that you want it to stay in. The cold blue you can get at a gun store as I think; at least in my area, Walm**t has stopped carrying Super Blue and only has the Perma Blue that you don't want.
That sound good.
I use black acrylic paint the same way if I'm working
on brass, etc.... .
Some times on steel I will use navel jelly, gun bluing,
or even CLR remover to give a lite bluing then sand the
face down, leaving a dark blackening in the cuts.
Steve, the dirty finger trick is good for a quick look during the engraving process.
Most of the old Eupopean and English engravers used to just rub their finger on their sharpening stone and then over the newly engraved area to see how it will look with the "dirt of ages" when it collects.
Not too sure if this would be a good idea if you were doing super fine bulino, though.
Most of the times I use black oil based painture solved in a little acetone to make it more liquid. We have different brands in Europe, so the best for you might be going to the closest fine arts shop, buying some different black paintures (ask for those that would be useful for painting little metal soldiers) and giving them a try. I had to buy three different brands until I got the right one!!. The brand I use is Humbrol. Acrylics might be difficult to clean afterwards.
The excess of painture can be wiped off with a cloth and acetone. For polished surfaces I use newspaper with acetone on it.
Take care, I'll write to you soon with exciting news!
I have used 44-40 gun blue, but warning, it will rust everything within reach overnight. I spilled some on my bench and forgot about it, and everytime I leave a tool on that spot, it gets rusty if left there long enough. Wipe off your work and neutralize it, and get rid of any rags or paper toweling with the cold blue on it. Brownell's Oxpho blue will do the same, but not nearly as bad.
I use the 44-40 for rusting steel, antiquing, browning brass, a lot of coloring and aging work. It is a terrible blue, as it will never stop rusting. Go figure.
I have some engraving on brass cartridge cases. It is rather small and is easily lost in the brightly shined brass. I see from several posts I can use Rustoleum paint to blacken the engraving but can I then spray them with Lacquer and the paint stay in the engraving? If not, please offer suggestions of materials that would give a good blackening result and also not fade, run or other wise get damaged by a coat of lacquer.
for a quickie blackening job, for photos or cellphone shot for client, i smoke the engraving with a candle flame, then wipe the surface clean with several layers of newsprint. (kind of like combining the techniques for a smoke print and a charcoal impression). it leaves the cuts dead flat black, fills the finest hairlines, and comes off with acetone.
note- i don't recommend this trick next to any sort of natural knife scales (MOP, etc.).
For a quickie look i use a soiled finger with a touch of oil , but usually use a black sharpie. If I want a softer more natiral look i soot a piece of metal with a candle then put a drop of oil on mynfinger, mix itbwith the soot and then rub it into the engraving I periodically clean all this off with some alcohol or wd40 so not to get a buildup