developing-out paper

[ dih-vel-uh-ping out, -vel- ]
/ dɪˈvɛl ə pɪŋ ˈaʊt, -ˌvɛl- /

noun Photography.

a sensitized printing paper requiring development in order to bring out the image. Abbreviation: D.O.P.
Compare printout paper.

Origin of developing-out paper

First recorded in 1915–20