U of S | Mailing List Archive | alt-photo-process-l | RE: Re: muddy gum print--help?

RE: Re: muddy gum print--help?


You could try sizing by exposing a pigment free layer of gum and dichromate.


-----Original Message-----
From: Charles Ryberg [mailto:cryberg@comcast.net] 
Sent: 12 April 2009 20:32
To: alt-photo-process-l@usask.ca
Subject: Re: Re: muddy gum print--help?


	Thanks for your help.  I'll reprint Monday (as I mentioned yesterday
stupidly ruined the example I posted).

	Does the order of printing matter?  The example was Cyan, Magenta,

	I can't size--asthma keeps me away from VOC's and my urban loft
provides no 
back yard or garage with fan.

	I use Fabriano Artistico Hot Pressed--it seems to stain less than

	My Lukas Process Magenta (PG2) does stain, though not as much as
some of 
the other magenta/reds I have tried. My Daniel Smith Hansa Yellow Medium 
(PY3) stains too.  The Daniel Smith French Ultramarine (PB29) stains very 

	I did a curve for each pigment at a concentration which seemed to me
to be 
the most pigment I could use.  Prints made with those concentrations and 
curves were even worse than the one I posted.  Trial and error led me to 
pigment concentrations of about 70% of maximum and exposure time of about 
80% of what I had determined "scientifically."  I suppose I could post the 
curves if you think it would be helpful. I use potassium dichromate on the 
cyan and magenta, ammonium on the yellow due to excessively long times with 
yellow and potassium.

	Exposure is BL tubes.  Timer is GraLab.  Registration pins by  Pro
(that's supposed to be a joke).

	Any help before I reprint (a better magenta?   a different printing
would be welcomed.

	Any help after I reprint, of course will be also welcomed.

Charles  Portland, Oregon