packing vs cardboard

packing and cardboard both are nouns.

Word	Noun	Adjective	Verb	Adverb
packing	Yes	No	No	No
cardboard	Yes	Yes	No	No

As nouns, cardboard is a hyponym of packing; that is, cardboard is a word with a more specific, narrower meaning than packing:

Other hyponyms of packing include composition board, excelsior, wood shavings.

packing (noun)	cardboard (noun)
the enclosure of something in a package or box	a stiff moderately thick paper
carrying something in a pack on the back
any material used especially to protect something

packing (adjective)	cardboard (adjective)
	without substance