RE: VDB

From: Loris Medici ^lt;[email protected]>
Date: 10/17/05-01:50:49 AM Z
Message-id: <001901c5d2ef$7e0f5d40$f402500a@altinyildiz.boyner>

Hi again,

"...There's TOO MUCH D-max in silver gelatin and quadtone inkjet, so it
ruins
you..."

Definitely, but I must add that I'm very happy with the Dmax I get with
Cyanotype 2 and Ziatype. Actually, what I don't like in Vandyke printing
is the fact that I can't get "acceptable Dmax" with just one coat...
Having to lay two coatings is boring.

"...maybe that "dedicated brush" is one of the
kind that just lays on enough emulsion for platinum? A foam applicator
may
slosh on more fluid, possibly the total amount in one coat you get with
two?...

Well, I use 1ml of sensitizer per coat for print size around 7x11. Do
you find this too little?

I didn't understand the issue with fixer... You're saying if I try to
fix an extra 1 min. I may get more Dmax? I don't experience bleaching
when fixing my VDB prints (maybe because I use a very weak fixer -
albeit change it every 3 or 4 prints - and fix for a very short time)...

Regards,
Loris.

-----Original Message-----
From: Judy Seigel [mailto:jseigel@panix.com]
Sent: 17 Ekim 2005 Pazartesi 06:08
To: alt-photo-process-l@sask.usask.ca
Subject: RE: VDB

On Sun, 16 Oct 2005, Loris Medici wrote:

> I guess good Dmax is a little bit subjective concept. Coming from
> silver gelatine printing (and quadtone b&w inkjet printing), the max.
> density I get with alt-process prints looks always weak to my eyes.

Hi Loris,

Your formula is the classic formula AFAIK, so I figure one or all of the

following:

Your standards are higher than mine;

There's TOO MUCH D-max in silver gelatin and quadtone inkjet, so it
ruins
you.

Papers today aren't as D-Maxy as the prewar (pre-WWII !) Strathmore I
had
a big stash of from NY Central Artists Materials (this I'm pretty sure
of,
BTW).

All of the above -- though I'm not familiar with that COT.... Still, a
couple of other thoughts -- maybe that "dedicated brush" is one of the
kind that just lays on enough emulsion for platinum? A foam applicator
may
slosh on more fluid, possibly the total amount in one coat you get with
two?

I also wonder (just curious -- your EXTREME precision has that effect!),

if a one-minute fix would give greater D-max. In my fixer tests there
was
a noticeable difference in bleaching between one minute fix and 2
minutes... I adjusted around it, and found 2-minute fix, or 1-1/2, was
fine (for my standards, anyway), still, I wonder....

But the whole fixing issue with VDB seems peculiar. A couple of my
students fell in love with the print color UNFIXED, and we found that
leaving the print unfixed, but with a good wash, it seemed not to change

after TWO HOURS re-exposure under BL fluorescents. That doesn't mean it
didn't change in time of course -- but it was at least possible to
believe
that the main function of the fixer was to darken the brown !!

cheers,

Judy

>
> I use the formula given in Wynn White's article @ unblinkingeye.com
> (http://unblinkingeye.com/Articles/Vandyke/vandyke.html). Formula
> says:
>
> Solution A
> Ferric Ammonium Citrate 9.0 gm
> Distilled Water 33.0 ml
>
> Solution B
> Tartaric Acid 1.5 gm
> Distilled Water 33.0 ml
>
> Solution C
> Silver Nitrate 3.8 gm
> Distilled Water 33.0 ml
>
> My chemicals are all good. My scales are all good (no problems with
> Ziatype, Cyanotype). My silver nitrate is white, it shows no
> precipitation and/or cloudyness when mixed with the
> distilled/deionized water I use. I use a dark amber coloured container

> with plastic caps (double caps). I use dedicated brush and plastic
> pipette for measuring coating solution and for application. Paper
> comes from its original packaging, no problems with other processes.
> No extra sizing (it's Cot 320; extremely good sizing on the front
> side). I know there are people printing platinum on that paper
> (another process that doesn't like gelatine sizing) so I guess its
> sizing is syntethic (aquapel?). I wash in 1% citric acid (in order to
> get rid of all unexposed sensitizer), I use plain 2% sodium
> thiosulfate fixer (no other chemicals added). Fixing time is 1 min. I
> expose right after drying the paper (5mins flat, then 25mins cold air
> fan).
>
> I get good Dmax by double coating and toning in gold before fixing.
> Never got good Dmax by single coating.
>
> Regards,
> Loris.
>
> -----Original Message-----
> From: Judy Seigel [mailto:jseigel@panix.com]
> Sent: 16 Ekim 2005 Pazar 08:11
>
> To: alt-photo-process-l@sask.usask.ca
> Subject: RE: VDB
>
>
> On Thu, 13 Oct 2005, Loris Medici wrote:
>
>> I'm sure I can't get even close to 1.2 with one coat VDB (subjective
>> comment: didn't measure, don't have a densitometer). Your 1.5 is very

>> close to semi-matte RC paper max. density (which is around 1.6
>> IIRC)... If I were getting such density I'd never bother with double
>> coating. I have Stonehenge paper sitting somewhere, will try it for
>> VDB
> when I will have time...
>
> I'm puzzled by the reports about insufficient VDB density... also
> emulsion ruination... I've used single coat VDB emulsion aged nearly 2

> years, plated out in the bottle, full of black precipitate, etc. etc.
> without problems and with good d-max.
>
> Wondering about:
>
> Is it possible a weaker formula circulates? What formula are folks
> using?
>
> Are all chemicals known to be good?
>
> Do you trust your scale? (That's a relatively small amount of silver
> nitrate, so truth in weighing matters.) Is the silver nitrate still
> white?
>
> And the water: We had a problem when the silver precipitated out as
> soon as it was added to the water, BEFORE combining with the other
> solutions. The hardware store had sold us tap water in a "distilled"
> water container. (On a hunch I brought it to the chem dep't which
> confirmed.)
>
> (I note that I was mixing the silver solution in a babyfood jar with a

> metal cap... When it precipitated right out, I thought it was the cap.

> I suppose the cap didn't help, but it was the water.)
>
> Are you sure your container is light tight? Not all colored plastic
> is. (I kept the brown glass bottle, with black plastic cap, in a dark
> closet when not in use.)
>
> Are you using a *dedicated* applicator -- say, foam brush that doesn't

> go into anything else?
>
> Does the paper lie on a *clean* surface for coating? (If stroke
> extends over the edge & onto a dirty surface, it picks up stuff.)
>
> Are you gelatin sizing? VDB does NOT like gelatin size.
>
> And fixer -- I found that two minutes in a plain fix of (percent I'd
> have to look up, but much weaker than standard fix) was the longest
> and strongest you could use without bleaching. (I probably have it
> somewhere, probably in P-F, but it made an enormous difference.)
>
> Also, I mention what maybe most folks know, but the books seem to have

> wrong
> -- The first rinse, in plain water, before fixing, should not be just
"until
> the water runs clear." A student did a variables test and found a much
> brighter deeper print with a 5 minute rinse before fixing.
>
> Heat drying the emulsion kills D-max, but storage before exposure and
> before development can also cut densitity. And probably more variables

> I'm not thinking of now...
>
> cheers,
>
> Judy
>
>
Received on Mon Oct 17 01:51:42 2005

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