In 1804, Sir John Leslie observed that a matte black surface radiates heat more effectively than a polished surface, suggesting the importance of black body radiation.

Then the process is repeated but this time, the copy film is masked by the reverse matte, which excludes light from the foreground area already exposed (fig.

The way it does this is it comes out at night, crawls to the top of a sand dune, and because it's got a matte black shell, is able to radiate heat out to the night sky and become slightly cooler than its surroundings.