Chroma Key Paper: Common Problems in the Studio
Chroma key paper can be very useful in helping you on a green screen shoot. But, the thing to remember about it is that it is there for support. It’s meant to fill in the blanks here and there, not carry the show. There are a few common problems with chroma key paper that hold it back from taking on a greater role.
The biggest problem about working with paper backgrounds, and this includes seamless backgrounds, is that paper can easily bend with creases becoming visible. It happens so effortlessly and that makes the paper useless to us. We want a smooth background that is a consistent solid color. A crease causes a small shadow, and that causes a headache when you go to key out the green later. Once the paper is bent, it is no longer any good.
True chroma key green paper costs more than regular construction paper, and yet it is practically the same material. This paper is especially easy to burn through due to the fact that once it’s bent, it’s garbage. Don’t use chroma key paper in situations where a cloth green screen could be used instead. It’s just easier that way.
Can’t Be Cleaned
Once the paper gets dirty, it’s done. If someone accidentally steps on it, then that’s it. You can’t clean paper. And, on a film set, it is very easy for stuff to get dirty.
What It Is Good For
Chroma key paper does have it’s good uses. It’s great for covering objects in a green screen shot that you can’t paint. Just use some chroma key green paper tape to hold it in place.
It’s also great for covering screens on TVs and monitors in shots that will later have an image added to them. It's not practical to shoot a shot with an actor and live monitor in it because usually the monitor operates at a different rate than our frame, which causes it to look like poor quality. Also, the lighting in impractical because monitors are bright. You either have to have the monitor properly exposed with the rest of the shot under or have the rest of the shot properly exposed with the monitor too bright. A piece of chroma key paper taped over the monitor solves this problem because you can just add the monitor's image in later during post production.
And last but not least, it’s great for covering little areas that might get missed with paint or a cloth green screen.