[alt-photo] Re: Gum Printing: Looking for some wisdom

[Marek Matusz]

Jennifer,
 
I forgot that I posted these tests a while back
 
https://plus.google.com/photos/105732508998271877151/albums?banner=pwa&gpsrc=pwrd1#
 
Marek
 

> From: darkroommanager at cornell.edu
> To: alt-photo-process-list at lists.altphotolist.org
> Date: Mon, 11 Mar 2013 18:26:52 +0000
> Subject: [alt-photo] Re: Gum Printing: Looking for some wisdom
> 
> Hello all,
> 
> I am reporting back with the tests I made last Friday. I was going to mix
> new Ammonium Dichromate, but I did not have a new bottle. So, I decided
> to retest my original test of Ammonium Dichromate. You can view the tests
> here: http://www.flickr.com/photos/93779173@N03/sets/72157632974249458/
> 
> I think that I now have a good jumping off point with these tests. This
> week I hope to work on the calibration of the QuadTone Rip negative.
> 
> Thank you for your help!
> Best,
> Jennifer Gioffre
> Teaching Support Specialist
> 
> Architecture Art and Planning
> Cornell University
> 120 Tjaden Hall
> Ithaca, NY 14853
> 
> Office: 607-255-4207
> Fax: 607-255-3462
> jmg393 at cornell.edu
> darkroommanager at cornell.edu
> 
> 
> 
> 
> 
> 
> 
> 
> On 3/7/13 1:56 PM, "Kees Brandenburg" <workshops at polychrome.nl> wrote:
> 
> >Hi Jennifer,
> >
> >As we are talking about gum, let's not forget this variable. What gum
> >arabic do you use? Premixed or self mixed, and at what concentration and
> >baumé? I'm using a 14-14,5 baumé self mixed gum. This is about 26-26,5%
> >
> >Looking at your exposure times for cyano and van dyke, compared to mine
> >(6 and 4min) I would say that you would end up somewhere around 10
> >minutes with your bank of UV and normal gum sensitivity. I find your
> >pigment concentration rather low. With 'normal' strenght gum I am using 1
> >gram per 20ml gum for winsor blue and lamp black on gelitin/glut sized
> >paper and never see any stain.
> >
> >With dichromate I'm a 'replenisher'. When the bottle seems to empty with
> >a coming workshop or project, I make some new and fill the bottle up.
> >From time to time it stands for several weeks or more.
> >
> >kees
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