"If it can be written, or thought, it can be filmed..." STANLEY KUBRIC
From Encyclopedia PRO
Internegative is an intermediate copy of a film, made on a very fine-grained stock, and used to make a greater number of prints than it is practical to make from the A&B Rolls.
Internegatives are made on the exact same stock as Interpositives. The film processes usually go from one polarity to another, that is:
Photographer shoots a Positive image and the film ends up as a Negative. The original Negative is printed onto stock that comes out as an interPositive The interPositive makes an interNegative, and finally The interNegative makes the Positive print.
There are some films (reversal films) that can go from positive to positive or negative to negative but are not used very often so are not included in this discussion.
The Internegatives are the workhorses of the industry. These are the elements that make the thousands of Release Prints for the theaters. When an Internegative wears out during printing, a new Internegative is made from the Interpositive and release printing resumes.
The question comes up as to why don't we just use the Original Cut Negative to make the release prints. One can easily see that each time the Cut Negative is run through the printing machine there is a hazard that the film could be damaged. Since the Cut Negative is the only source you have, that risk would be unacceptable.