Bad green screen and lights result in an uneven tone on camera. Some areas look darker than others. The darker areas become harder to chroma key out afterward, especially if there are transparent objects or fine hair within the shot.
The most important aspect of shooting any type of green or blue screen project is the appropriate lighting. If the subject isn't lit correctly or the green screen is too dark, too bright, or uneven, chances are you'll have problems pulling a good matte
<u><em>In contour drawings, crossing lines is one way to indicate this. A line that is drawn to show the edge and surface ridges of an object. ... This type of line can denote instability and tension.</em></u>
