Paint the logo in a ring?

I saw rings about damiani, alfieri and another companys that they put
the name of this companys in the arm of the ring with a colour.
always black, how dit it? what is the product that they paint the logo
of the company?.. thanks

Sorry if I didn’t quite understand the query, but if you stamp the
ring then use liver of sulphur (or some other variant) on it it will
be black on and hold the colour despite polishing as it is reccesed
from the hand stamping process. Rio Grande carry stamps and the
chemical and at least one variant that is less hazardous and works
just as well (white bottle, light black writting, the name slips my
mine and is currently in storage with the rest of my metal wokring
stuff sigh I need some workspace…

Kindest,
K. David Woolley
david.woolley@unb.ca