kessler
Hello,
I’m a fan of the two-bath selenium toner (bleaching in red potash salt, followed by development in a selenium/sodium sulphide solution, see, for example, relevant recipes in the ‘Darkroom Cookbook’), because I prefer the resulting violet-brown tone to the yellowish-brown one produced by thiourea toning.
The downside, however, is unsightly brown staining in the highlights on prints on baryta paper and a brown discolouration on the paper backing, which cannot be removed even after hours of soaking.
Has anyone else had similar experiences and/or perhaps knows of a remedy?
Best regards,
Martin
Gast
Hello Martin,
In his 'Master Photographer's Toning Book', Tim Rudman describes these problems as 'selenium staining'. He suggests the following remedy:
1) A two-bath fixing process using a concentrated (e.g. 1+4) rapid fixer
It is particularly important to remove all undeveloped silver from the image during toning. Even traces of silver can cause the stains described during exposure to the toner.
2) A bath in hypo-clearing agent, especially for baryta paper
The fixer leaves the silver; the hypo-clearing agent removes the fixer and dissolved silver residues from the felt. A bath in carbonate solution is less effective than a special clearing agent, but better than just water.
3) Rinse thoroughly
4) Then tone
A few days ago, I reported on very similar problems with sepia toner. I have now got the issue under control using a two-bath fixing process and longer washing. Funnily enough, I ran into these difficulties with PE paper because I don’t usually fix and rinse it as thoroughly as I do with baryta (where I use a two-bath fixer and hypo-clearing anyway).
I hope this helps you in some way, although I don’t have any personal experience with two-bath selenium toner (I’ve always used Kodak RST so far).
By the way: what formula do you use? I’ve still got a few grams of selenium in the lab; I could do with using them (don’t worry: I’ve got the paper, mask, etc. – I’ve got a bit of a background in this from work...)
Best regards, Jens
