text vs written matter

text and written matter both are nouns.

Word	Noun	Adjective	Verb	Adverb
text	Yes	No	Yes	No
written matter	Yes	No	No	No

As nouns, written matter is a hyponym of text; that is, written matter is a word with a more specific, narrower meaning than text:

text (noun)	written matter (noun)
the words of something written	matter to be printed; exclusive of graphical materials
the main body of a written work (as distinct from illustrations or footnotes etc.)
a book prepared for use in schools or colleges
a passage from the Bible that is used as the subject of a sermon

text (verb)	written matter (verb)
to send a message by SMS or similar text-based messaging service