I do this for 6x7 negs(strips of 3).
a friend does this as well with 6x17 negs/trannys. less chance of scratching vs printfile sleeves. no pulling out/pushing back in. Just sleeve the whole roll, and cut the frames out.
get the v-fold lock sleeving. there are ones that are a tube-type design. get the v-fold ones. less chance of scratchage.