key out

verb keys out · keying out · keyed out

1. transitive To remove (something) or make (something) transparent in a scene through the use of a chromakey. Blue screens are much easier to use when filming dark scenes, where there shouldn't be much light. Also, they're easier to key out around objects that melt into the green screen, like blond hair. Still, blue screens are more expensive to use as they need a lot more light to work properly.