Re: Re: muddy gum print--help?
Hi,
I'm sorry about your asthma. I think lack of size is your problem. I would try sizing with starch between each layer and see if that makes a difference.
Regards
Davidh
On Apr 12 2009, Charles Ryberg wrote:
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