The film (135) is slit in the slitter at the bottom of the picture and rolled into the right chamber of the Minox cassette. The slitter is simply 3 razor blades side by side and a pressure plate (to the right of the slitter) on top. The film is pulled through by hand to about 45-50cm lengths. A 36 exp. 135 film gives 4 - 6 36 exp. Minox films depending on how long leaders you want. Leaving a short leader out of the chamber it can then be taped on to the take-up spool which is inserted in the left chamber and covered with its lid in daylight. The film in the two cassettes in their boxes have not yet been taped to the take-up spools to the right.

Minox flim slitter (from "xkaes" on eBay) for 135 film. Left: with pressure plate in place. Middle: three rasor blades cut the film to te corrct 9.4mm width when the film is pulled through. Right: The slitter uses electrical tape on surfaces that touch the film emulsion to prevent scratches.