Ni*el"lo (?), n. An impression on paper taken from the engraved or incised surface before the niello alloy has been inlaid.

Ni*el"lo (?), n. [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.

Ni*el"lo (?), n. An impression on paper taken from the engraved or incised surface before the niello alloy has been inlaid.