NIELLOING

Verb

nielloing

present participle of niello

Source: Wiktionary

NIELLO

Ni*el"lo, n. Etym: [It. niello, LL. nigellum a black of blackish enamel, fr. L. nigellus, dim. of niger black. See Negro, and cf. Anneal.]

1. A metallic alloy of a deep black color.

2. The art, process, or method of decorating metal with incised designs filled with the black alloy.

3. A piece of metal, or any other object, so decorated.

4. An impression on paper taken from an ancient incised decoration or metal plate.

Source: Webster’s Unabridged Dictionary 1913 Edition