Steve Shapiro (sgshiya@redshift.com)
Mon, 18 Jan 1999 21:06:35 -0800
Adam,
So, when are you going to try it and report back?
SS
-----Original Message-----
From: Adam Kimball <akimball@finebrand.com>
To: William Laven <wmlaven@platinotype.com>;
alt-photo-process-l@skyway.usask.ca <alt-photo-process-l@skyway.usask.ca>
Date: Monday, January 18, 1999 7:55 PM
Subject: Re: Micro pipettes and K. chlorate %solutions
>Thanks William for you the note-
>
>Well, first off, that email was merely a hypothesis- and like any
hypothesis is
>quite possibly totally wrong- I thought I'd through it out there for what
it is
>worth... if anything.
>
>My point was merely that if you are looking for the ultimate single-coat
print, a
>good place to tighten things down would be the amount of metal and iron
that
>actually gets on the paper. When I rod coat, I routinely end up with
sensitizer
>that I push right off the paper at the end. The paper (mainly Platine)
simply
>doesn't take as much emulsion as I'd like to put on it. Now, maybe the
addition of
>some water doesn't affect this - maybe the paper fibers will take on extra
water
>after it has stopped taking on sensitizer? I have no idea. However, if it
isn't
>the case, I think my point has some some validity (a drop at least?) - get
more
>metal and iron onto the paper, and get deeper blacks. So, if you use a
highly
>saturated ferric oxalate, a saturated metal salt solution - with as little
water
>present as possible, you might get deeper blacks. I don't brush coat at
all, so I
>speak only from rod coating experience...
>
>Eric Nielsen - you out there? Any opinion on the matter? I know you've
spent some
>time thinking about saturation. Rudiak - anything? Weese, Sullivan, where
are the
>platinum printers - counting drops?
>
>I'd personally love to learn more about this..
>
>-Adam
>
>
>
>William Laven wrote:
>
>> >Every time you add extra water into the emulsion you are effectively
lowering
>> >the amount of metal per sqare inch that actually stays on the paper.
Using
>> >more sensitizer doesn't work - because the paper only takes so much
>> >(especially rod coated papers). So, if you can absolutely limit the
amount of
>> >water by using very saturated metals and iron you theoretically achieve
a
>> >coating with a richer emulsion, and ideally you get better blacks
because of
>> >it.
>>
>> I don't follow the logic of this. Unless one adds copious amounts of
water
>> to the sensitizer which results in much of the sensitizer not soaking
into
>> the paper and being "dried away" then the amount of metal per square inch
>> is identical without water or wit a little.
>>
>> I commonly double coat on Arches Platine: 6 drops FeOx Sol.A, 5 drops
metal
>> for each coat on a 4x5. I use dichromate in the devleoper for contrast
>> control. In an experiment to see if I could duplicate the results of
double
>> coating (higher dmax most notably) with less sensitizer I made a mix of 9
>> drops of FeOx Sol. A and 8 drops of metal and 5 drops of water which I
then
>> split into two portions which were used for double coating. The idea was
to
>> have one and a half times the amount of sensitizer normally used for
single
>> coats with the water added to make coating easier. That method results in
a
>> print superior to a single coat and just a teeny tad weaker than a double
>> coat as I normally did it with double the amount of sensitizer. If there
>> were significantly less metal per square inchg as you claim, my 1 1/2
>> sensitizer-double-coat would have been much weaker. As long as the
>> sensitizer gets into the paper -- with whatever amount of water added to
it
>> -- the same amount of metal is there.
>>
>>
*************************************************************************
>> WILLIAM LAVEN PHOTOGRAPHY
>>
>> Workshops and tutorials in Platinum/Palladium printing and Zone
System.
>>
>> 1931 23rd Street, San Francisco, CA, 94107
>> 415-647-9432 (voice) 415-647-9438 (fax)
>> wmlaven@platinotype.com
>> http://www.platinotype.com
>>
>>
*************************************************************************
>
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