Thiourea toning problem.

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Thiourea toning problem.

Post by markbau » Sat May 25, 2019 10:25 am

A few years ago I started using Thiourea and had some problems where the lighter tones never fully redeveloped. Today I had another go. I have been using the formulas and procedure outlined in the Ephrams book. Anyhow, my question is what am I doing wrong? My light grey clouds all but disappear in the bleach but don't come close to coming back fully in the redevloper. Ephrams suggests immersing the print in hot water if this happens but it didn't do anything for me. He also says to tone at 25C which I did. I'm using Ilford MGFB warm developed in D72 fixed in Ilford rapid 1-4. The prints were toned in Kodak rapid selenium and washed well before bleaching. I noticed that a very similar formula appears on page 308 of the Cookbook, the only difference is that the bleach contains Sodium carbonate which I did not add to my bleach. Any suggestions on how to get my lighter tones to fully redevelop?

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Re: Thiourea toning problem.

Post by sanchell » Sat May 25, 2019 4:43 pm

Sodium carbonate is an alkali that works as an accelerator. Why don't you try adding that and see what happens?

Second, Ilford uses a lot of hardener in their paper, far more than when many of these formulas were written. This came about as part of a three-way competition between Kodak, Agfa, and Ilford for the lucrative machine print market. Hardener makes the paper resistant to both scratching and toning.

I would recommend trying Adox Premium MCC 112 VC FB available from Freestyle Photo,, or Foma Fomatone 132 Classic VC FB Warmtone, also available from FS.
Do it in the Dark,

Steve Anchell

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