Re: Brush Marks on Platinum/ Pd. prints
John Rudiak (wizard@laplaza.org)
Fri, 03 Apr 1998 18:54:04 -0700
Stephen R Harrison wrote:
>
> If it's not one thing, it's another !!!
> I am printing a 12x20 inch continuous tone negative and using sodium
> dichromate / Potassium Oxalate method of development .I carefully coated
> my platinotype paper with 4.5 ml of ferric oxalate #1 solution ( 72 drops
> equavalent) , no #2 restrainer and added 4.0 ml of palladium and .5ml of
> platinum. I used a acrylic rod in the application. The paper gradually
> buckles ever so slightly making the puddle pusher ineffective as slight
> pools of sensitizer were apparent. I then used a brush ( Hake) and smooth
> it all out. Later after development and clearing, I note the presence of
> slight brush marks in the highlight areas of sky. Good old sky and the
> problems that inevitably occur in the sky in pt printing. Possibility #1 is
> that I brushed too long and the drying left the brush marks. Possibility# 2
> is that I used too much sensitizer and had to brush too long to spread the
> sensitizer. What are others experience in doing large prints which are
> difficult to coat? I have had problems in the past with 14x17 in using the
> puddle pusher exclusively whereas on smaller prints, there is no problem in
> the exclusive use of the glass rod for coverage. I don't need a brush
> there. I find I do need a brush and glass rod in the application of
> sensitizer on these larger prints. Do others find this? Does double
> coating of the paper help in this problem?
>
> Stephen Harrison
Hey Stephen- what do your "brush marks" look like? I have come across
batches of Platine which show a distinct mottling in the highlight areas
of the print. What batch number are you using?
While you are using almost twice the amount of sensitizer than I do on
12X20's, I don't think that would contribute to the marks, as I have a
good friend that uses a lot of sensitizer also and makes beautifully
smooth prints. He doesn't use Platine, and he doesn't use a puddle
pusher. He prints much larger than 12X20 as a rule, coats with one of
those expensive japanese brushes.
Iuse 6 ml. total on the 12X20, and use a foam brush to coat. I am doing
a portfolio for a client right now of 12X20 negs on Platine, so I'm with
you. Maybe you are abrading the paper by pushing the sensitizer around
for too long a time period. I would say it takes me less than 10 seconds
from when I pour the emulsion onto the paper till I stop brushing. I
stop while the paper is still wet and let it sink in by itself. If you
are brushing long enough for it to start to dry that could very well be
the cause of problems.
This assuming the paper itself is not at fault.
Good luck, hope this helps
John
--
ÿWPCÛ