U of S | Mailing List Archive | alt-photo-process-l | Re: VDB nasty staining problem

Re: VDB nasty staining problem


Let me venture a guess: the stain may be a result of how you used the citric acid "clearing bath". It's important to wash off the excess emulsion as the first step. When you soak the print in the "clearing bath" some of the excess silver nitrate could get imbedded in the paper instead of being washed off, and that would produce stain.

So try skipping the citric acid bath and see if you still get stain. I never tried using citric acid, but when my students agitate exposed vandyke in a tray of water instead of rinsing the prints in running water, they got stain. That's without gold toning, but I suspect the toning is a separate issue.

Please do report back if you find out.

Good luck.

Sam Wang

-----Original Message-----
From: david drake [mailto:daviddrakephoto@sympatico.ca]
Sent: Monday, April 30, 2007 3:22 PM
To: alt-photo-process-l@usask.ca
Subject: VDB nasty staining problem


I'm having a bad staining problem with gold/thiourea toned VDB prints.
The staining appears during the final wash. It's fairly consistent
throughout the print (there are some lighter blotches) but clear around
the edges of the coated area. I'm thinking that the sensitizer is not
being cleared properly and there is some residual silver but I don't
understand why the stain only appears after the fix and in the final

I use a citric acid clearing bath for 3 minutes, then wash for a 3
minutes, then gold/thiourea toner (8 minutes), then wash, then alkaline
hypo for 4 minutes and then 1% sodium sulphite clearing (2 minutes),
then final wash (30 minutes).
I have been using Stonehenge White paper. I also just started using a
Richeson 'magic' brush today, which was new today to my process (I have
previously been using a puddle pusher).
At first I thought that the paper may have been not dry enough but
longer drying times after coating didn't help. I always air dry at least
20 minutes between and after the two coats. the coating and drying area
was between 50-60% RH.

I have been making palladium toned VDB's on Stonehenge paper for quite a
while and have never had this problem. I started with the gold toner in
the last month.
Yesterday was quite a frustrating day!

thanks for any advice.

david drake photography