- My personal approach is to only use cartridges with removable end caps, you know the ones made to be reloaded, not minilab discards.
- I use 3/4 inch or the equivalent metric size masking tape and use about three inches of tape per roll.
- The tape goes all the way around the spool, and grabs onto both sides of the film, just the way film makers do it.
- The better masking tapes work well, the cheap stuff is too thin and tends to curl into a ball as I measure it out so the premium brands are better. That eliminates the cheap tapes from 3M (Highland, etc.) and the house brands from outfits like LePage.
- The quality 3/4 tapes from 3M and Duck are very good, I buy the 3M stuff from a place that sells professional masking tapes, got my last roll from a place that sells automotive paint and supplies (I guess when folks are ready to spend $100+ for a can of paint they don't mind buying a better grade of tape).
- I would love to get a roll of the tape that Kodak used to use on the Tmax 3200, that stuff is awesome.
I also have a roll of minilab spicing tape around here somewhere I plan to give a whirl.
I loaded about 80 rolls of Kentmere this semester alone for my students using this approach and did not have any film come off a spool. Our last batch of cartridges were from Photographers Warehouse and seem to be better than the really thin walled ones we got from somewhere else last year. We reuse until the things until they wear out.
At home I use an assortment of Kodak Snap-Cap Magazines, old Ilford and Agfa cartridges, and old mini-lab cartridges with removable ends, Agfacolor and various private label films from Agfa and Konica. Some of the later are DX encoded. I also like the older plastic cartridges, but the new ones are horrible.