What (exactly) is the stuff manufacturers put on the S and F letters associated with the safety?  Is it paint, enamel, what?

I have become tired of squinting at the rear ladder sight on my No. 4 and want to "paint" the microscopic numerals to make them stand out.  I think I would like to carefully paint these numbers and letters to make them stand out.  As I recall, my brother's muzzleloader had gold leaf(?) in the bottom of the stamped letters.

On a related note, how does one permanently blacken stainless sights?

Thank you, gentlemen.

You can use the lacquer sticks available from Brownells... check the engraving section.  Stainless doesn't take very well to any of the chemical treatments... that's why its stainless!  I use black paint airbrushed and baked at 300 F.

Edited for spelling even after proof reading twice!  Duh.

I've seen some work done with the laquer sticks and it looks pretty good.

Eventually I'll probably buy some and use them on some stuff but right now I'm lazy.