Re: dichromate stain

Christina Z. Anderson wrote:
>

>
> > Katharine said: rules and explanations almost invariably turn out to be
> wrong, or at
> > least right only for a very particular set of circumstances, so not
> > useful for gum printers in general.
>
> I respectfully disagree. If I may wager a bet, this list does not give a
> hoot about "one gum truth" but about a set of variables which may or may not
> be the answer. Clues. That is how I learned gum--troubleshooting had a
> number of answers listed for every problem. Maybe only one answer was my
> cause, but that did not disprove the others. As I've said before, one black
> swan does not prove there are no white swans, only that there are more than
> one type of swan.

> The fact that (I wager here) probably 90% of gum printers experience stain
> at least once (gross understatement) in their gum career leads me to
> believe it is a bona fide issue worthy of discussion.

Chris, I think perhaps I haven't made myself clear, because you say you
disagree with me and then go on to say basically what I thought I was
saying. I'm certainly not objecting to the discussion of issues; heavens
if I didn't think dichromate stain was a legitimate issue for
discussion, I wouldn't have been here answering questions about it for
the last six years! So I think we'll just have to agree to agree here;
I'm not sure who you're arguing with but it's not me.

>
  Thus, knowing the
> possible contributors of stain as exposure, type size, type paper, type
> dichromate, development, strength dichromate, etc. etc. is beneficial.
> There cannot be one cause of dichromate stain across the board because of
> the incredible variables in the gum process.

Again, that's exactly what I was saying.

>
> > > Judy said: Another reason I have less staining is probably that my
> development times
> > > tend to be long. I gather that some folks develop a half hour or less...
> I
> > > usually develop an hour and up... and I have noticed that the really
> long
> > > soaks come out wonderfully white -- and assume that, at least in part,
> > > that is why I rarely if ever need a clearing bath.
> >
> > Then Katharine said: Funny, Christina was just arguing yesterday that the
> reason she GETS
> > dichromate stain is because she exposes hard enough to require longer
> > development, and today Judy argues that she DOESN"T get dichromate stain
> > for the very same reason, which just shows how far we are from any
> > useful explanation for this.
>
> Correction: my variable is not development, but exposure alone.

 Judy is
> talking about development.

Yes. I shouldn't have said they are exactly the same, because you're
coming from the exposure side and Judy is coming from the development
side, but surely you're not arguing that they don't go hand in hand?
Judy couldn't develop longer than "normal" without losing something of
the image, if she didn't expose long enough to make that possible, for
example, and you said, I thought, that you expose harder because of the
way you develop with spray, than you would if you were developing in a
bath. So it seems to me like you're looking at the same thing from
different sides. But if it's important to you to separate them, that's
fine with me.

>
> To observe dichromate stain on prints I will clear half a print and see the
> difference. Always intriguing, and that even goes for the prints that don't
> look stained.

Just in case there's anyone here who doesn't believe me when I say I
don't get dichromate stain, I've done just what Chris proposes and
posted it here:

http://www.pacifier.com/~kthayer/html/Current.html

 
Katharine Thayer
Received on Mon Jun 14 19:48:22 2004