Richard Knoppow (dickburk@ix.netcom.com)
Tue, 25 May 1999 21:19:12 -0700
At 01:26 AM 5/26/99 +0100, you wrote:
>Hi Folks,
>
>Richard points out that the recipe I quoted was in fact Nelson's. Sorry! I
>do, actually, remember reading somewhere that hypo-alum toned prints should
>be fixed, but cannot remember where, or what reason was given. As stated
>earlier, I disposed of many books a while ago and don't now have very much
>info on toning, but Mallinckrodt's Chemistry of Photography (6th. ed.,
>1940), which Judy sent me, says something. For straight hypo-alum, it does
>not mention fixing, but does say to make sure that prints are fully toned, I
>would guess because colloidal sulphur is inevitably trapped in the emulsion,
>which would continue to tone over time if there remains silver for it to act
>upon.
>
>Mallinckrodt gives Nelson's, plus two other hypo-alum-gold recipes (for
>Defender and Haloid papers). These recipes (which are, in fact, identical!)
>are of a different type to Nelson's, and a fix is specified for both. I'll
>just quote the Defender version, along with notes from the text, and what
>the Haloid Co. has to say about using the same formula. (If anyone's paying
>attention, this recipe also looks very like the Walley recipe -as far as I
>can remember it - which I mentioned in my last post, and which didn't
>impress me very much on the papers of about 10 years ago. But don't let
>that discourage you - I might not have mixed it properly!)
Formula snipped... thanks for posting it.
Now, with that prompting I discovered I have both the Mallenckrodt book
(in fact a couple of editions) plus I found both formulas in other sources.
Well gorsh Mr. Disney...
I think however, that the puzzle is solved by the fact that the
Gold-Sepia toners all allow _partial_ toning. The stop bath is used to stop
the toning so that it doesn't continue while washing. Regular hypo-alum
toners are used to tone to completion. I bet that's the difference.
Which suggests that if a Hypo-Alum bath is used for partial toning, to
obtain split tones, that it should then be followed by re-fixing.
Haloid BTW gives a method of making Hypo-Alum toner from ordinary
hardening fixing bath. It requires boiling the bath to sulphurize it.
Somehow I have the feeling that this is not a great formula to make up in
the kitchen.
----
Richard Knoppow
Los Angeles,Ca.
dickburk@ix.netcom.com
This archive was generated by hypermail 2.0b3 on Thu Oct 28 1999 - 21:39:35