S&R --- to answer your question, I offer the following.
A french gray finish is usually accquired by first bluing followed by removing the blue leaving a light phosphate on the steel. It is easily rusted.
Engraving that has a light background has no texturing (beading / mating ) done to the background between the leaves of the scroll.
Engraving with a dark /textured background is the opposite of the above and has background work done.
I find that color case hardening the action and removing the surface color (not in the engraving) will allow me to del. an action/part that has the hardness of a cased piece, is highly rust resistant. I can also give it a simple treatment that will give a soft french gray color to the case. FWIW, Ken
