RE: (Gum) Multi prints???

Oops! Sory, higher the pigment ratio, higher the dicromate ratio should
be (in order to compensate for the emulsion contrast increase due to the
augmenting pigment load)... The logic in the second part of my message
is wrong, I guess it's the fault of my "morning drowsiness" :) Sorry
again.
 
Anyway, there's a limit with the dichromate dilution (AFAIK, around 20 -
25% for AD, 10 - 13% for PD). As you will not be able to increase the
strength of your dichromate above these figures, you should compensate
for this in your negative by decreasing its contrast. This may not be a
good option for the specific image. That was my point.
 
Regards,
Loris.

-----Original Message-----
From: Loris Medici [mailto:loris_medici@mynet.com]
Sent: 14 Aralık 2005 Çarşamba 08:55
To: alt-photo-process-l@sask.usask.ca
Subject: RE: (Gum) Multi prints???

 
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 03:02:51 2005