In the process of organizing all my old negs, I've come across a number of C-41 films that were developed at Walgreens some years back and which have a protective plastic layer laid over them. It's not quite a sleeve, as it doesn't wrap around the sides, but each side has a strip of clear plastic/PET overlaid that's glued to the film along the sprockets. It's fairly easy to peel off, and was obviously applied automatically in the machine before being cut. It's kind of a clever idea actually, but at first sighting I was totally flummoxed! I've never noticed this before and have never heard of it. What is this called? I assume it was some implementation by Kodak and I'm curious if the glue used is safe for long term storage, though I'd assume it is. Anybody know what I'm talking about? Got a patent number by chance?