RE: Re: muddy gum print--help?
Charles You could try sizing by exposing a pigment free layer of gum and dichromate. John. -----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? Folks: Thanks for your help. I'll reprint Monday (as I mentioned yesterday I stupidly ruined the example I posted). Does the order of printing matter? The example was Cyan, Magenta, Yellow. 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 Arches. 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 little. 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 Art (that's supposed to be a joke). Any help before I reprint (a better magenta? a different printing order?) would be welcomed. Any help after I reprint, of course will be also welcomed. Charles Portland, Oregon
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