Whatever works best for you. Personally I mount all of my transparencies. The reason is that it allows me to store and organize them individually. I can put all similar images into the same storage sheets and then if I am looking for an image of a back lit cattail I go to the sheets that store cattail images and find the one I am after instead of having to search though piles of stored sheets because I remember that two years ago I shot an image but I cant quite remember exactly when it was. When I first started out, I used to keep all the slides from a roll of film together, but that quickly got out of hand. Now I group according to subject, or in a few cases I keep a specific sequence of slides together because they are telling a story. That said, I do keep entire rolls of negatives intact and organized by roll. But for the most part I blast most of if not the entire roll on one subject and so I am still organizing by subject more or less.(posted 8875 days ago)