Which bleach for print redevelopment (lith)?

Discussion in 'B&W: Film, Paper, Chemistry' started by andreios, Dec 18, 2012.

  1. andreios

    andreios Member

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    Friends,
    I was cleaning up my darkroom and almost tossed in the litter bin a bunch of screwed up prints - overexposed and such. Then in the last moment it occurred to me that I might still have some fun with them and try bleaching them and redeveloping them again in lith (or simply bleach and tone).

    I have found two basic formulae of the bleach - one is based on copper sulphate, sulphuric acid and sodium chloride (I presume I can't use regular salt since it is iodized...) - the other being the potassium ferrricyanide and potasium bromide formula.
    Is any of these two better for this purpose or could I use either of these for my purpose?

    Thank you.
     
  2. Ian Grant

    Ian Grant Subscriber

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    I'd use the Potassium Ferricyanide/Potassium Bromide bleach, it's useful for other purposes as well.

    If you used the Copper sulphate bleach I wouldn't be worried by small traces of iodide, it's quite possible to use iodide based bleaches. It's worth experimenting with different bleaches though as they all affect the finla colours in different ways.

    Ian
     
  3. andreios

    andreios Member

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    Ian, thank you for clearing this up for me.
    A.
     
  4. paul_c5x4

    paul_c5x4 Subscriber

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    The copper bleach can give some interesting tones, but do use a very dilute developer solution as it is easy to miss the "snatch" point - When I last mixed some, I used the cheapest table salt I could find at the local supermarket.