Jonathan C Hall (platinumprint@mediaone.net)
Thu, 21 Jan 1999 16:35:50 -0800
Check out Tween 20 from Bostick & Sullivan helps and is claimed to be the "magic
bullet" for helping with handcoated photographs. I am just now buying some as they and
Luis Nadeau have convinced me. So I can not give first hand experience. The stuff is
cheap.
Adam Kimball wrote:
> 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
> >
> > *************************************************************************
This archive was generated by hypermail 2.0b3 on Sat Nov 06 1999 - 10:06:43