In the book, Way Beyond Monochrome, Ralph Lambrecht describes a binary numbering scheme for plastic film holders. He suggests notching the inside lip of the lower flap to create corresponding patterns on the exposed film's edge that when lined up with a ruler equate to the holder's sequence number. I was interested in trying this, but have had little success with it. Since his suggestion is to notch only the inside lip, the outer lip of the holder still creates a shadow that, in my experience anyway, prohibits adequate exposure in the notched area. Has anyone else tried this? Perhaps other's would be willing to share how they track exposures when shooting lots of film. Thanks for your thoughts.