From: Eric Neilsen (e.neilsen@worldnet.att.net)
Date: 02/13/00-06:39:44 PM Z
Nick, There have been some good points within the other answers. Here are some
more. The #1 and #2, if within the traditional context, refer to Ferric Oxalate
and Ferric Oxalate with Potassium Chlorate. The Potassium Chlorate will break
down over time and will have less of an effect than it once did, giving you
prints with less contrast than anticipated. Speed and Fog and two aspects to
certainly pay attention to when printing. A bad ferric will give you poor
blacks and fogged edges or highlights.
Run a test on it to see if it has converted to ferrous. Jeffrey has a good
description of how to do that on his site, or if you can get a copy of Dick
Stevens kallitype book, he also spells out a test.
As for the bad prints, I would agree that your batch may be contaminated with
something. I find that with paper, the fewer hands that have handled it, the
better.
Coated Paper Storage
If you plan to use the paper later, or find that you can not use what you have
prepared due to lack of time, etc., keep it dry- really dry! It is important to
remove the moisture in the paper. If you are working in a room that has a 72%
humidity, that may be hard to do without the use of a desiccant as Dan
mentioned. Also make sure that it is safe from light and heat, as all three
contribute to the deterioration that Jeffrey points out.
Where did you get your paper in the first place?
I find that 55% to 60% to be my optimum RH for my workroom and 62% to 67% in my
humidity chamber.
Eric
Nick Makris wrote:
> Hi again,
>
> I spent the last two days coating/printing Cranes Platinotype (which I
> commented about previously) and living with the imperfections in the
> resulting prints. I have added a step to my working notes which suggests
> that after cutting the paper to size, I should inspect the surface for
> imperfections of any kind - including shiny spots that won't take the
> sensitizer and also which won't take any sort of spotting color. Hopefully
> my next batch will fare better - I found 20% rejects.
>
> That being said, I must add that in the last two days, I have answered some
> of my questions and have created some others. For example:
>
> How does outdated #! & #2 ferric oxalate affect the resulting print? I
> have some that is 8 months old and that works on some prints and
> not on others.
>
> My work area has a fairly consistant RH of 65-72% - rain or shine. What
> is optimum?
>
> How long after coating/drying is acceptable to leave the coated stock
> unused and how should it be stored?
>
> I like the color and surface texture of the Cranes 90# cover (aka
> Platinotype) - if I buy more am I apt to run into the same level of quality?
> Would someone recommend a substitute and a source for it?
>
> Many thanks for listening,
>
> Nick
-- Eric J. Neilsen 4101 Commerce Street, Suite #9 Dallas, TX 75226 214-827-8301 http://home.att.net/~e.neilsen
This archive was generated by hypermail 2b29 : 04/24/00-04:37:10 PM Z CST