A time and developer saving hack

 N.B. I don't claim to have originated this hack and to some this is obvious, however it's a great way to cut down on time and chemicals used when developing 120 roll film in a Paterson Super system 4 development tank.

The bottom of the Paterson tank states how much liquid is required to develop a film. 

290 ml for 35mm film

370ml for 127 film

500ml for 120/220 film

The interesting bit is the 120/220 comment.  What that tells me is that each spiral, that is provided by Paterson, can hold either a 120 roll film or a 220 roll film.

220 roll film was a hack carried out by film manufacturers to allow photographers more photos per roll and still use the film in existing cameras. To do this they doubled the length of the film.  However when rolled onto a standard 120 spool, complete with full length backing paper, the diameter of the roll exceeded the flange on each end of the spool.  This flange prevents light from spoiling the film through the end of the roll.  Making the flange bigger would mean that the spool wouldn't fit existing cameras.  The hack that they came up with was to provide only enough backing paper to cover each end of the film for daylight loading and unloading but leaving the center length of film with no backing paper.

This being the case, two rolls of 120 will fit onto a standard Paterson spiral.  Therefore for 500 ml of developer you can develop 2 rolls of 120 film.  A 50% saving in chemical.  Also developing 2 rolls of 120 film at once cuts down time by 50%. Neat eh?

So how do you get 2 rolls onto the spiral.  I like to do the following.

1) Load the first roll of 120 film onto the spiral as normal.

2) When you get to the end of the film you will notice that the film is attached to the backing paper using masking tape.

3) Very carefully peel the masking tape off of the backing paper and continue to load the film onto the spiral until the end to which the tape is attached goes past the loading gate.

4) At this point start loading the second 120 roll by attaching it to the masking tape (sticky side will be towards you).

5) Continue to load the second 120 roll onto the spiral and you will find it all fits on.

I've used this method a lot and I'm happy that it works.

BTW when loading 120 film on a warm day pop the film and spiral into the fridge for half an hour or so. The gelatin becomes very sticky in warm weather and makes loading the spiral a nightmare. cooling it all down really helps.