Re: tonal inversion and pigment loads

On Jan 27, 2006, at 9:20 PM, Katharine Thayer wrote:

>
> On Jan 27, 2006, at 7:44 PM, Yves Gauvreau wrote:
>
>
>> Katharine,
>>
>> I should have explained myself more clearly on this. If you look
>> at Tom
>> image again, you'll see that as the exposure increases, the number
>> of "paper
>> white" step(s) gets lower and lower suggesting that the lowest
>> exposure
>> (time) must not be allowed to invert at all, otherwise you get
>> what is
>> called "inversion" stains (for now). I think we can all agree on
>> that.
>>
>
> Actually I can't, because I'm not sure what you are saying. Are you
> saying that the answer is that you should expose so long that you
> push the print tones all the way up to 21 so that there's no room
> for stain, making all the steps from 1 to 17 black? And then just
> develop for the next month to get rid of the tone back down to the
> four actual tonal steps? This doesn't seem to me a reasonable
> thing to do. And maybe that's not what you're saying.

Sure, if you expose long enough you could probably run the stain off
the end of the scale, so in that extreme sense stain could be said
to be exposure-dependent; you're right about that. But in any sense
that relates to gum printing practice, which is what I was talking
about, it makes a lot more sense to eliminate the stain by sizing or
changing the pigment load than it does to expose so long or develop
so long as to eliminate the stain by exposure. And if the experiments
I showed last week (at the bottom of my website page) are any
indication, it's not necessarily even an effective way to eliminate
stain, once you get past a certain level of overpigmentation. At any
rate, within any reasonable exposure time, the stain remains, so
exposure is irrelevant to the stain in practice, it just adds to
development time without affecting the stain. But sure,
theoretically you could eliminate stain if you exposed long enough to
run the hardened gum up to the end of the scale, but so what? would
be my question.
Katharine
Received on Sat Jan 28 10:48:57 2006