substantive dye vs dyestuff

substantive dye and dyestuff both are nouns.

Word	Noun	Adjective	Verb	Adverb
substantive dye	Yes	No	No	No
dyestuff	Yes	No	No	No

As nouns, dyestuff is a hypernym of substantive dye; that is, dyestuff is a word with a broader meaning than substantive dye:

substantive dye: dye with a high affinity for cellulose fibers (cotton or rayon etc.)
dyestuff: a usually soluble substance for staining or coloring e.g. fabrics or hair

Other hypernyms of substantive dye include dye.

substantive dye (noun)	dyestuff (noun)
dye with a high affinity for cellulose fibers (cotton or rayon etc.)	a usually soluble substance for staining or coloring e.g. fabrics or hair