U of S | Mailing List Archive | alt-photo-process-l | RE: Stock Paint:Gum Solutions?

RE: Stock Paint:Gum Solutions?



Don,
It is a different color layer every day, usually in batches. If I decide I need to add 2nd cyan to the print as the 4th layer it goes to the cyan batch. My 5th or even 6th layer are usually  non primary colors and quite often with a color mask designed for that specific spot application. I stil use premixed stock solutions for those.
Marek




Date: Thu, 23 Oct 2008 17:21:09 +1300
From: don@sweetlegal.co.nz
Subject: Re: Stock Paint:Gum Solutions?
To: alt-photo-process-l@usask.ca


Hi Marek
Do you add each layer on a different day?.  Does that mean 5 or more magenta nights in a row, or do you cycle though the colours?  Too many straight cyan nights for example might be bad for one's equilibrium.
Also I guess your system of work means each layer of a given colour is exactly the same.  I should perhaps acknowledge that my own colour IQ on the recent test was quite spectacular in some parts of the spectrum - I achieved virtual skyscrapers for my blue/green discrimination.
Don Sweet
 
----- Original Message -----
Sent: Thursday, October 23, 2008 2:07 PM
Subject: RE: Stock Paint:Gum Solutions?

Loris,
I found that using stock solutions is the way to go to get consistency. As Chris noted modern organic pigments do not separate and stay suspended in gum solutions forever, just a little shake and you are ready to go.
My thalo blue stock is 15 ml tube (Daniel Smith) to 150 cc of gum. Magenta, which is quinacridone rose (PV19) is 1 tube to 120 cc of gum, my standard yellow now is PY150 and it is 1 tube to 300 cc of gum. I have to say I did not use PY151 that you mention and Daniel Smith does not carry it. Most of other colors that I use require about 150cc of gum for proper balance. ANother color that is very strong is PR254 (Ferrari red), I have a stock of 1 tube to 300 cc. If you do not want to mix that much stock you can mix it with 150 and at 1 part of gum  for printing. I add 0.3 to 0.5 part of saturated ammonium dichromate to 1 part of gum/pigment. I found no compelling reason to add more and then wash it down the sink. I add 1 part of water for 1 part of gum. This dictates the thickness of gum in a finished print and would change somewhat depending on paper absorbency. Lastly, I measure my gum solution and pour the exact amount for a given negative size, for eample 8.5x11 requires 3cc of sensitizer for my paper (Fabriano Artistico).
If you have 10 prints to do just mix a batch and measure a predetermined amount for each print. My workflow is to do a single colour is a session, which is 2-3 hours and allows for 8 to 12 prints. So tonight is magenta night.
You do have very similar cyan and magents dilutions and as I noted I did not ever use your yellow. I seems that your concentrations would be about 2x as much as I use and that would give you very strong and saturated prints, somewhat difficult to balance midtones, higlight and shadows in my opinion. AT these concentrations I run into some stain issued. I prefer to work in somewhat weaker layers and add pggment in more then 3 layers, on the average say about 5. You can always improve a prints that is too light with another layer or two or three.
You are a fast learner and progressing well.
Marek

> Date: Wed, 22 Oct 2008 08:13:39 -0600
> From: zphoto@montana.net
> Subject: Re: Stock Paint:Gum Solutions?
> To: alt-photo-process-l@usask.ca
>
> OK this is it--one last email before I get on the road. Have to teach a gum
> workshop in Missoula MT 200 mi away and I have to have my hubby drive me
> there because I can't drive with a knee brace. He has to sit in a town for
> two days entertaining himself so you can imagine he's one happy camper.
>
> I mix all pigments 15ml tube in a total volume of 60ml because that is the
> size nalgene bottles I have.
>
> At time of use I cut my pigments with plain gum--thalo gets cut as much as
> 1+5, yellow maybe 1+2, magenta maybe 1+3, depending.
>
> Stock solutions are a cinch to use, and I only have problems with the heavy
> pigments which settle and separate into a sludge on the bottom--nickel
> titanate, cerulean, cadmiums. Since I no longer use these colors, mixing
> stock is not a problem for me as far as separation is concerned.
>
> I think your thalo may be too concentrated, but I notice a progression of
> yellow-magenta-thalo which I also do as far as strength.
>
> One more thing--at time of use I may decide to do an undersaturated print,
> too, in which case I cut all pigments way more.
>
> There are several list members who have this down to a real
> exactitude--Marek, Dave Rose used to, and they'll tell you exactly how much.
> OH, you could do a search for Dave Rose's posts a few years back but he did
> use powdered pigment.
> Chris
> __________________
>
> Christina Z. Anderson
> http://christinaZanderson.com/
> __________________
> ----- Original Message -----
> From: "Loris Medici" <mail@loris.medici.name>
> To: <alt-photo-process-l@usask.ca>
> Sent: Wednesday, October 22, 2008 7:56 AM
> Subject: Stock Paint:Gum Solutions?
>
>
> >I was reading handprint.com's "The Secret of Glowing Color" page, which
> > contains very good and interesting information, especially in the section
> > "Not Black, Not Light".
> > (http://www.handprint.com/HP/WCL/tech16.html)
> >
> > I slowly feel the need of making stock paint:gum solutions, in order to
> > get more consistency and ease of use. Mixing small amounts of paint:gum
> > solutions is hard to do consistently, especially with strong colorants and
> > small image sizes. (Because squeezing small amnt. from the tube is not
> > easy!)
> >
> > I decided to make stock solutions as listed below:
> >
> > Yellow PY151 1:2 (1:4 final) -> 15ml paint + 30ml gum
> > Magenta PV19 1:3 (1:6 final) -> 15ml paint + 45ml gum
> > Cyan PB15:3 1:4 (1:8 final) -> 15ml paint + 60ml gum
> >
> > Since the stock paint:gum is further diluted 1:1 with dichromate, the
> > actual paint dilution in the coating solution will be exactly the half of
> > what it is in the paint:gum solution. (See inside parenthesis.)
> >
> > This question goes to users of stock paint:gum solutions (such as
> > Katharine and Christina):
> >
> > Do you find above figures close to ideal? What is your experience with
> > those pigments? Anything to pay attention / be careful about using
> > paint:gum stock solutions?
> >
> > Thanks in advance,
> > Loris.
> >
> >
>
>



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