RE: PT/PD and humidity redux

Mark, I routinely humidify all coated paper in a wooden enclosure ( a box)
with a humidifier that sounds a lot like yours. I leave heavier paper in
for a minimum of 15 minutes after drying and typically 25 minutes before
exposure. I let thin papers like Bienfang 360 sit in the box for at least
10 minutes. This is for a typical 50/50 mix. If I am using more platinum, I
reduce the humidity to increase the speed and keep the cooler color.

Eric Neilsen Photography

4101 Commerce Street

Suite 9

Dallas, TX 75226

http://e.neilsen.home.att.net

http://ericneilsenphotography.com

-----Original Message-----
From: Ender100@aol.com [mailto:Ender100@aol.com]
Sent: Tuesday, March 02, 2004 10:06 AM
To: alt-photo-process-l@sask.usask.ca
Subject: Re: PT/PD and humidity redux

Hi Carl,

I knew humidity was a factor in giving a longer scale, I guess I didn't
expect that much difference with the "re-humidification". Well, it sorta
scared me.... hehehehehe Just imagine doing this with some Palladium with
no restrainer at all... hmmmmm Let's see, I'll need a negative with about
5.0 density hehehehe

The tonal range just seemed to stretch out in all the steps.

I did notice more printing out effect, which I suppose increases the self
masking to a degree.

I am not sure what you mean by "veiling" of the blackest values? What would
I look for?

I humidified and re-humidified with my trusty Holmes cold air humidifier.
It has a watersoaked filter and a fan. I did not put the chemical in the
water that they give you to preventing liming... I thought it might do
something to the print having that in the moisture. The fan directs the
humidified air straight up, so you can sit the paper on it's edge between
the louvers and it just floats vertically by itself, since the air pressure
is equal on both sides. It's kinda fun to watch. Sometimes I sit for hours
watching it and forget to make my print. hehehehe

I wonder if thicker papers hold more humidity? That would make sense.

I was going to borrow Chris water spritzer and spritz the rubber matte in
the vacuum table of the Nuarc just before I put the print in... maybe just
the area around the print... and see if that cooks up a little steam with
the Nuarc....maybe if I do all these things I can get a perfectly black
sheet of paper with no image whatsoever hehehehehehe

Mark Nelson
In a message dated 3/2/04 5:52:11 AM, cweese@earthlink.net writes:

Mark,

Longer scale with more humidity is expected. You say the Dmax remained the
same, so did the extra range come in the form of three more steps in the
high values? Did you notice any veiling of the blackest values? Also, did
you notice an increase in printout--pre-development image formation? You
don't mention what equipment you humidified with, but two minutes of added
treatment in a 60% environment could have made for a really humid sheet.
Finally, you'll find different papers have different humidity reactions and
different 'ideal' humidity levels.---Carl
Received on Tue Mar 2 20:42:22 2004