I was just thinking of all those auto thread projectors out there and how the leaders need to be nigh on perfect
for threading up, when it gets to the take up, it usually gets creased when fed into the slot in the spool and might need
trimming on the next showing. An idea might be to already have a length of leader, or just a strip of anything 8mm wide a few feet long already set up on the spool with a little piece of tape, masking tape is perfect, as your leader comes through, just tape it to the lead already on the spool, no
creasing to your leader on your film, result perfect for the next showing. Just a thought.

Hugh a good idea on my 16mm prints I now attach about two feet of black spacing before what ever leader is there.That way I can always cut of the creased section and if there is a problem while threading even when doing it manually you can afford to loose the black spacing.

It may be a lot of trouble, but after I feed the film through an auto-thread mechanism, I stop it and manually attach it to the takeup reel. I know some machines are designed to 'catch' the leader onto the takeup reel without ever touching it, but I don't trust that feature as it will possibly crease the leader further down than it should.

Yes I agree Tim and sometimes the take up does not catch and the take up spins faster and faster and suddenly snap leader completely buggered if not beginning of the film!!

Although my standard 8 machines are manual thread, I've been adding no less than three to four feet of leader lately to my precious reels!

True, I was just thinking of the times the auto exits the film through the slight crease that previous attaching to spools will cause,
where if it goes through okay, stop, stick it too the tail and restart, resulting in perfect leader for next time.

The projectors I use do all need the dovetail trimmer as opposed to the Elmo style beveled edge trimmer, but I have to trim them only once. Once trimmed they thread each time even after the anchored 45 degree 20mm flat section you get at the beginning at each leader after making the take up reel for the first screening, from placing in the reel holder/ slot.

Hugh nice one. That's a very old professional projectionists "trick of the trade ".
Glad you have picked up on it.