Hi
Lamp Black or carbon black is one of its many other names that has been used for hundreds of years in inks and rubber tyres and black pigment in plastics are just some of its many uses and to us gun folks it is the soot from an oil lamp used traditionally when closely fitting metal parts in a gun i.e. Barrels to action using the thickness of smoke. Now there is some speculation about Lamp Black it may be carcinogenic but the jury is still out on that subject I think and I am of the age now I dont care.
Now the older or more traditional method of highlighting engraving was to use Indian ink which is a mixture of Lamp Black shellac and solvent which you apply to the surface quickly using a cotton wool swab and then wiping off with a cloth lightly moistened with Alcohol. Once it has dried in the engraving it is mat black adheres well and waterproof though not permanent because it is removable with Alcohol.
Black shoe polish is a wax that never dries totally hard so not a good choice for a gun because the oils in your skin will make it soften and you will more than likely at the worst case have black marks on your hands or they may just look grey.
Artist materials suppliers are a good place to purchase Indian ink and it is not costly.
