To Pre Wash or Not?

This post is for users like me who predominantly use 120 rolls film.

The “To Pre Wash to not” you film before developing discussion bounces back and forth on many internet forums but here I out line my experience recently (2023).

For a while not I have been left with 120 negatives having a pronounced “purple” colour and for a little while I thought it was my change over to using FX-55 vitamin C developer but thankfully it was not.

For now the next bit of info is not aimed at 35mm films so its up to you if you want to pre-wash 35mm film or not.

120 roll film has an anti-halation dye layer with dye, you will know if your chosen film has this if you prewash and see the colour of your spent developer is green (Fomapan) or Pink / Purple (TMax, TRI-x, FP4+ and others).

Note: I prewashed a roll of 35mm HP5+ and not colour change in the spent water was noted.

What I found to my relief was doing a 120 roll film pre wash for a few minutes, just water at 20 degrees C, cleared around 95%+ of the dye before developing the film.

I also noted that when dumping the spent developer there was barley any colour change.

Note: Kodak advise with their B&W films that fixing for an extra few minutes, say 2 or 3, is also helpful clearing any anti-halation layer left and I have found that fixing all my B&W films for a few extra minutes has no negative (sorry) effect on my films.

My stop bath and fixer has also been left clearer when dumping back into their bottle for reuse.

Washing also has a positive effect of clearing the dye layer and my wash flow after fixing is now

2 x 3 min under the tap to over flow to flush out most of the fixer left then use the Ilford wash method of 5,10 & 20 agitation washes and then using filtered water leave to soak for a minute or two.
Ilfotol Wetting agent (10ml to 2000ml) using filtered water as a final soak for a minute or two.

I keep the final Ilfotol bowl under where I am going to hanging the negatives to dry. This allows me to run the negative through my squeegee a couple of times with the waste going back into the bowl.

So for me the prewash and thorough wash after developing has delivered negatives without the dye of if it is there then it is so minimal I barely see it.

I think this deserves a video made to complement this post and I will make this very soon.

So in short. Prewash your film and if the water is coloured by dye in the film, 35mm,120 or sheet, then make a prewash part of your film developing workflow.

DC x

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