Re: A little gum test

To use a no doubt exaggerated analogy: Imagine if someone was printing
on gel-silver paper and got a totally black print, and came to the
conclusion that the all-black paper being a "low-contrast" print, the
problem must be the contrast range of the paper, and the solution must
be to print with higher-contrast paper, rather than to reduce the
exposure.

It may be that Kate is using a light that is too intense for the
saturated ammonium dichromate, in which case she does need to go to a
lower concentration to slow things down and prevent overexposure, but if
so, let's be clear that the factor that necessitates the change is the
speed of the saturated dichromate, not its contrast range, which is
completely obscured when all the tones are blocked.
kt

Katharine Thayer wrote:
>
> Kate Mahoney wrote:
> >
> > Hi Mark,  Less contrast with the saturated solution was
> > postulated....so I'thought I'd give it a whirl. I have been getting
> > rather flat prints so this is good news. The results (to me) show some
> > of the reason why I've been having some trouble with this technique -
> > obviously too much amm.di. I think the reason why the tones are better
> > is that mostly I've just been overexposing with the amm. di. at the
> > more concentrated level...
>
> Thanks Kate, this provides some confirmation for a suspicion I've had
> for some time, that when people say that saturated ammonium dichromate
> prints flat, perhaps what they really mean is that they overexpose when
> they print with saturated ammonium dichromate. I have never observed
> that saturated ammonium dichromate prints flat when properly exposed.
> That not only the shadows but the highlights were blocked (I'm assuming
> you mean after a reasonable development time) suggests that the problem
> was related to significant overexposure, as you suggest above, rather
> than to the contrast range of the saturated dichromate per se.
> kt
Received on Mon Dec 15 03:59:31 2003