Re: one more mordancage post, long...

[Nate Apkon <nmapkon@rcn.com>]

Chris:

Awesome!!!!  You are some busy lady. What great info.  Thanks.

Your finding that the stronger HP causes more yellowing seems logical to 
me.  I wonder if there might be the result of some residual Mord 
solution in the paper after the 1st wash that reacts with the 
redeveloper and, since HP is a strong oxidizer, the stronger  the HP the 
more the oxidation and yellowing.  The fact that the RC paper does not 
yellow I think lends some credence to my theory.  Your room light 
results are most interesting.  Since my darkroom is relatively small I 
have been doing all my Mord work either in my garage or outside, all in 
daylight.  Maybe, with a respirator :-) , I can do some under a safelight.

I'm still looking for my copy of the French info, my filing system is 
sad...no, make that pathetic, but I did find the info from Luminos. 
 They recommend a 2 part mix.  Part A:  30gm Cupric Chloride, 80ml 
Glacial Acetic Water to make 1L.  Part B: 20 Vol HP.  Mix EQUAL parts of 
A & B at room temp.  That's quite different than Craig's with 35ml HP/L. 
  I know I still have the French paper & will send it as soon as I find it.

I noticed Jon's email to you.  You should know, that among his many, 
many talents, he makes great wine.

Nate

Christina Z. Anderson wrote:

>Cor,
>     I think I may have found an answer to your problem of not liking the
>yellowing of fiber papers!
>     Today I did my final (yeah, I've said that before) testing on
>mordancage.  I tested 40v, 20v, and 10v hydrogen peroxide.  I tested doing
>the process on fixed prints, unfixed prints, in room light, under safelight.
>I tested Ilford glossy MGIV, Ilford warmtone, Oriental (old, fogged), Agfa
>MCC, Ilford Matt, and Forte polywarmtone glossy--plus Oriental RC and Forte
>polywarmtone RC.  I'm a mess, I stink, and I have little bits of emulsion
>everywhere--but I found out what I wanted!
>     What I found is that yellowing was greatest 1. with the highest
>strength peroxide (!)  2. on fiber paper 3. doing the mordancage under
>regular room light  4.with not fixing the mordancaged print upon completion.
>When I did the mordancage under safelight with less strong h.p and fixed
>before having the print hit room light it did not yellow.  Try it for
>yourself and prove me right :)  Wash your print thoroughly before fixing
>tho, because it stinks to high heaven when the print hits the fixer with any
>mordancage solution left in.
>     Nate--for you, I found out this.  For some flukey reason, sometimes a
>print doesn't work.  Then the next print (same paper, same printing session)
>does.  I thought maybe, as you did off list, that a print that didn't work
>was somehow selenium toned and I just didn't realize it.  I do find that
>selenium toned prints do not mordancage as well, but an occasional print
>doesn't make it either for no reason.  But Shultz had said in his Shutterbug
>article that the age of the paper affects whether it bleach etches fast or
>not, and the Oriental paper I used that was old and fogged did not budge in
>the mordancage so there could be truth to what he says. Hence I would
>tentatively say selenium toned prints and old paper are tough, until I prove
>myself otherwise.
>     I've simplified the process to be user friendly:  2 T. of copper
>chloride and 80ml of glacial acetic; mix in a liter of water in that order.
>Then equal parts of h.p with that.   No hauling out the scales.
>     I've also found that it is immensely better to start with a dry print
>than a wet; less time to infuse the chems.
>     According to Neblette the h.p does the softening of the gelatine, the
>copper chloride does the changing of the metallic silver to silver ions.
>This is why the stronger h.p. veils the emulsion--it really destroys it fast
>and furiously.  I think this is also why the stronger h.p makes the print
>yellower--it softens the gelatin too much so that in developer it absorbs
>too much and stains, especially when not fixed.
>     I used dektol mixed normally--1:2.  I did not find any reason to dilute
>the developer.
>    Why i tested three kinds of h.p is to see if the 3% drugstore type did
>make it.  That is about 10v.  It does work, albeit slower, but I had to rub
>quite a bit to get the emulsion to flake off.  It does not "veil" the
>emulsion off as the stronger volumes do.  Rubbing off the emulsion was
>simplified with a plastic scouring side of a sponge.  But I found that
>sometimes the 40v removed too much emulsion and I think I may prefer 20v
>from now on, especially because of the yellowing issue.  Somewhere around 20
>I did not notice yellowing, but how close to 40 I could get I do not know.
>     I also tested the mordancage sabattier--1.develop an exposed print  2.
>rinse  3. mordancage  4.rub off emulsion under room light 5. redevelop.
>It's OK--you essentially get a black and white negative image which has its
>uses...
>     I also found Ilford paper consistently mordancaged well; Forte did well
>most of the time with an occasional fluke, as did Agfa, and Oriental.
>     RC paper does stay nice and white but the emulsion comes off so readily
>that you can't really expect a veiling thing to happen and stay put unless
>you are so very careful and don't wash, etc...
>     Enough said,
>Chris
>
>
>