Emulsion Batch definition

A sequence of numbers on a film that start after the emulsion type.  Once a film is created, every batch receives a number so one can shoot a single sequence with any one of the batches.  Combing batches in the past was more difficult because frequently the emulsion batches could be “off” which of course affected the visible effect in the film.  However, mixing emulsion batches is not such a bad thing nowadays because emulsion batches have become more consistent.  However, they can still be a little off today.  The ideal way is to shoot a single sequence with one particular batch.