drop cloth vs piece of material

drop cloth and piece of material both are nouns.

Word	Noun	Adjective	Verb	Adverb
drop cloth	Yes	No	No	No
piece of material	Yes	No	No	No

As nouns, piece of material is a hypernym of drop cloth; that is, piece of material is a word with a broader meaning than drop cloth:

drop cloth: a large piece of cloth laid over the floor or furniture while a room is being painted
piece of material: a separate part consisting of fabric

Other hypernyms of drop cloth include piece of cloth.

drop cloth (noun)	piece of material (noun)
a curtain that can be lowered and raised onto a stage from the flies; often used as background scenery	a separate part consisting of fabric
a large piece of cloth laid over the floor or furniture while a room is being painted