Spool Down definition
The process of winding a 400 foot roll onto four 100 foot daylight spools in order to use it in a camera that is capable of handling 100 feet of film. The process is done in total darkness so that the roll remains unexposed. The film must be wound totally through in one complete cycle and then spooled down. This ensures that the edge numbers are printed on the correct side and are not printed on the work-print.