>
> I regularly double coat Platine paper. Diluting the second coat with
> distilled water is helpful because the second coating is absorbed much more
> quickly than the first; a little more solution helps considerably. Start by
> adding 1/4 the quantity of sensitizer. Between coats I let it air dry from
> 5-15 minutes; it changes with the humidity, batch of paper, phase of the
> moon, phase of my mood, etc etc, just like every other step in the process.
> I then use a hair dryer on it, but dry only the sensitizer side -- dry the
> front AND back of the paper after the second coat. Its important that your
> drying procedure be consistent and repeatable.
>
> >Second question : In the sodium dichromate method of contrast control, is
> >any restrainer such as Hydrogen peroxide needed for the KOx #0 solution,
> >that is no drops of sodium dichromate.? Is the evident grain of the pure
> >Kox solution paper dependent?
>
> You don't need a restrainer for the KOx #0 solution
>
***
I only single coat, as that works best for me. However, everyones
working methods are different and you need to try it both ways to
determine if there is an advantage for your system with double coating.
I prefer to use hydrogen peroxide in the sensitizer rather than in the
developer for contrast control, but again, because this works better for
my particular working procedures. Is your FeOx fogging? This would be a
reason to use H2O2 in the Kox #0.
To address the second part of your question regarding the granularity
(or mottling) in the unrestrained KOx, I would have to say that it is
paper dependant. One batch of Platine is not the same as any other
batch, as I have had the misfortune to discover. I have, since the
inception of this paper, had to add small amounts of tween to control
washoff in the developer, where in the earlier batches this was not
required. I recently purchased a batch of Platine for the production of
a portfolio which showed a marked granularity in smooth toned areas of
the print above zone six, with unrestrained sensitizer. I tried
everything I could think of to eliminate this garnularity, double
coating, no tween, more sensitizer, glycerine, etc., but had no
success. I was able to exchange this lot for a lot with an earlier
batch number through the good graces of the distributor. The initial
results were terrible as the coating went right through to the back of
the paper in a spotty manner, some of it staying where it should (on the
surface) and other areas going right through. Eliminating the tween in
the sensitizer kept it on the surface and resulted in significantly
reduced (but not totally absent) granularity in smooth toned areas. Do
you know what batch of Platine you have? To see if it is the paper, just
make another test on a different paper taht is compatible with this
printing process.
Regarding drying, I have found it advantageous to use a drying cabinet,
which is simply a box big enough to hold several sheets of the largest
size paper you use, with a hair dryer stuck in a hole of suitable size
in the bottom of the box. I have a thermometer stuck through a hole in
the top of the cabinet and when it passes 100 F (in my climate) I know
the paper is dry to print. I don't like the idea of a hand held hair
dryer blowing oxalate particles around my darkroom.
Best
John