U of S | Mailing List Archive | alt-photo-process-l | Re: Vandyke Question

Re: Vandyke Question

So contaminated FAC, bad silver nitrate, salt in the water source as per below:




There was a more recent thread on this white precipitate issue than these, above, but somehow I can't find it.

There is no better way to find out VDB problems than to teach to students, which I did this week, so this thread is timely for me. Anything that goes wrong, will.

1. Some had the silver plating which resembles reversal also, on the print--it seemed to happen for two reasons, one was overexposure and reversal/solarization very visible on a step wedge where the deepest brown occurs and then the next darker step starts the reversal process. Other plating issues due to the solution not sinking in enough to the paper and sitting in a puddle/being too thick in puddles/drying too fast with a blow dryer, very visible in puddle like marks especially in the dark borders. Arches paper doesn't seem to be too absorbent and plated easily; Weston paper is GORGEOUS so I would highly recommend Weston for VDB. One student did such a beautiful VDB print on it, it sings like a platinum. And last year a student did a final project of VDB on Weston and waxed it all....

2. Some had low contrast/dull prints--letting the solution sink in too far and not rinsing enough/being rigorous/agitating enough in both the wash bath and fix bath. Perhaps an inappropriate application of the curve, also.

3. Some had a few spotty yellow marks due to not getting out all the ferric--oxidation of the silver is pretty quick!

4. White precipitate--I did not experience this this year and don't think I have in the past, or if I did, I do not remember and it didn't do anything to the resulting prints. My silver nitrate, tartaric acid and FAC were a year old, all from Artcraft Chemicals. I do use grocery store distilled water.

5. Chemistry worked fine that was a year old but (silly me) I actually decided to dump it just to make SURE that would not be a variable for the students to have issues with this year. I won't do that again. My solution was perfectly fine and yellow when I brushed it onto paper and the print exposed well.

6. And (ta da) one student calibrated a PDN curve and printed on toilet paper from the building's bathroom. I have to say, toilet paper produces a gorgeous VDB chocolate brown--perhaps not terribly appetizing on toilet paper! Seeing 101 step tonal palettes on TP is quite the hoot.

----- Original Message ----- From: "Alberto Novo" <alt.list@albertonovo.it>
To: <alt-photo-process-l@usask.ca>
Sent: Sunday, February 24, 2008 2:17 PM
Subject: Re: Vandyke Question

Judy said:
But, given the far better care you have obviously exercised, my guess would be that there's another factor at work, that for instance one of your chemicals could be below par. Have you made the emulsion from these chemicals successfully, or with less hassle, in the past?
I don't print VDB since about eight years, but I remember I haven't experienced any trouble mixing the working solution. The only thing that happened to me was the different hue my VDB's had (cooler or warmer), probabily depending from the strength and temperature of the fixer (on the same paper). Now I am more careful about that, whichever the technique I am using.
So, I am aguing that the problem might be in the FeAmCitrate. Contaminants like chloride and sulphate, but also an excess of citrate, could be the responsibles.
However, if after filtering your solution gives you good results, never mind!