Re: (Gum) Multi prints???

Here's my chime, and I'll combine two posts into one:

if I'm referring to the same thing--exposure scale being number of steps on
a step wedge that print from step 1 to step 31 (or 1-21 on a 21 step) then I
am going to agree with Loris that pigment choice does affect that. So does
pigment load, dichromate choice, and dichromate saturation.

I match my curve of my digineg to the pigment load, pigment color,
dichromate percentage and type(15% ammonium dichromate), and time (whew,
sounds more complex than it is).

As far as duotones, maybe I'm missing a point here, but all you do is do a
color separation negative in photoshop, combine your blue and green negs at
50% transparency on top of one another (blue printing yellow traditionally,
green printing magenta) and use that to print your warm and the remaining
red neg to print your cool. It's easy as pie to do this, but maybe I missed
the duotone point.
Chris
If you take it to that extent, I would say even the color of the pigment
may affect the exposure scale of the emulsion (think of the difference
between curves for a blue layer and a yellow layer, or the difference in
the behaviour of a blue layer and say... a red layer - Christina can you
please chime in here? You should have a good deal of information on this
issue)... I don't think further diluting of dichromate in order to print
a heavily pigmented (therefore relatively high contrast) mix will
necessarily make possible using a relatively high contrast negative and
solve the problem presented here... Because decreasing the dichromate
ratio will make the emulsion more flaking-prone. So, the higher is the
pigment load, the lower should be the the dichromate dilution, the lower
the dichromate dilution, the lower should be the pigment load (if you
don't want flaking). Kind of a vicious circle...

Regards,
Loris.

-----Original Message-----
From: Ender100@aol.com [mailto:Ender100@aol.com]
Sent: 14 Aralık 2005 Çarşamba 04:37
To: alt-photo-process-l@sask.usask.ca
Subject: Re: (Gum) Multi prints???

Loris,

I am going to put my neck on the chopping block and venture to say that
yes, you would get a higher DMax with a more heavily pigmented mix (up
to point of failure/washing off), but that would not necessarily mean a
lower contrast negative would be required, since the exposure scale
would have more to do with the dilution of the dichromate than the
amount of pigment-exposure scale and DMax are different beasts.
Received on Wed Dec 14 08:36:35 2005