Joao,
First of all I would say that your fix is too strong for my liking and done for
too long. Of course you may compensate by increasing your exposure (to a
point).
Your color variation could be the result of humidity or the
"freshness" of the hypo. I use a 3% hypo and have to admit that I
haven't tested it to see when it has built up too much silver. My working rule
is to change the hypo after doing eight 12" x 9" prints or four
16" x 12". I cover the hypo in its pitcher overnight if I haven't met
that quota. If you want more consistency consider adding another variable to
your process. Toning with gold chloride / thiocyanate before the fix. I get
very consistent color when I incorporate this step.
Also if you have found VDB has suddenly turned ugly on you and no longer is
returning the love you have for it, mix up some fresh VDB and let it age 48
hours.
Here is my working method: Humidity between 60 - 70 percent
1. Tap water. Pre-rinse exposed print in tap water (face down is something new
I've been trying). Make sure the emulsion side of the print avoids the bottom
of the tray.
2. Gold toner. Tone with gold chloride / ammonium thiocyanate. (still trying to
resolve the palladium toner's effectiveness)
3. Tap water. In between rinse.
4. Hypo. For 45 - 60 seconds. 30 grams per liter although I mix up 60 g in 2 L
for a work session.
5. Tap water. In between rinse.
6. Hypo clear. Yes, I'm still using Sprint Fix Remover. Ever since reading
Sarah van Keuren's Non-Silver Manual.
7. Tap water. In between rinse.
8. Citric acid to get rid of any or as much of the remaining iron. Two minutes.
9. Tap water. Final wash. Ten minutes.
Hypo is an important step in resolving color, image density, and stability.
Don't ask me how it works. You should notice an initial darkening of the image
which is a pretty good preview of your dry down. Too long and you bleach away
density from all areas of the print. Poorly paraphrasing the Christopher James
book: silver links up in the hypo stage. I notice a gradual browning of my hypo
which settles to the bottom over several days which may be iron liberated
during the hypo stage. By itself water is not an efficient silver (chloramine)
chloride solvent.
Contrast: There is a contrast formula in the James book. Liam Lawless method
utilizes a mixture of ferric citrate and ammonium ferric citrate in the Part A.
Don't ask me how to use it. I adjust my contrast at the stage of creating
negatives since they are inkjet transparencies. There's also the option of
adding 10% potassium dichromate to the sensitizer for increased contrast.
I don't bother acidifying the step 1 water with citric acid. It will remove a
little bit of the iron and decrease the intensity of brown in the final print.
-francis schanberger
On Thu, Aug 6, 2009 at 3:54 PM, Joao Ribeiro Globo <ribeiro.joao@globo.com> wrote:
Hi,
I'm doing VDB on Arches Aquarelle.
I get different colors sometimes, usually dark brown but also reddish brown
sometimes.
Is there a way to control this?
Is there a way to control contrast of the VDB?
Process:
Hake brush to apply VDB
Expose
Wash in plain water for 5 min.
Fix in 5% hypo bath for 5 min.
Wash and dry.
Another question, if I wash the copy to get rid of the VDB solution, why do I
have to fix?
There is no more silver in the paper after washing, is there?
Thanks in advance,
Joao
--
francis schanberger
www.frangst.com