Crossword clue: a black colloidal substance consisting wholly or principally of amorphous carbon and used to make pigments and ink

The most common answer is lampblack (9 letters).

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

Possible answers

lampblack 9 letters wn-def

a black colloidal substance consisting wholly or principally of amorphous carbon and used to make pigments and ink

soot 4 letters wn-def

a black colloidal substance consisting wholly or principally of amorphous carbon and used to make pigments and ink