U of S | Mailing List Archive | alt-photo-process-l | Re: another 3 layer gum attempt

Re: another 3 layer gum attempt

Paul..You, Katharine and Joe have completely lost me! My guess is it has something to do with the Everclear that I started ingesting as I started to read this thread! This is not an RGB but rather a CMYK that I did this morning. My yellow was a cheap Cotman Cad Orange. I can not read the numbers (too small or the Everclear?) But, it is a cheap student grade pigment. I used an inexpensive paper, Canson Montval and exposed using black lights.  

I really wanted the yellow to be very prominent and I think that it worked well. My negs were very thin and I exposed for approx 3.5 mins and developed in hot water for about 10 mins. After the printing with cyanotype I sized with Gamblin PVA.

Going back for some more Everclear,

On Tue, Jul 21, 2009 at 10:24 PM, Katharine Thayer <kthayer@pacifier.com> wrote:
Well, this isn't necessarily an incongruity, as by "contrasty" I wasn't meaning anything like the range of a palladium negative, just the black digital negs I used to make that  were somewhat denser than the negatives I use now.   As I mentioned, the negatives I use now are so thin they are useless in the sun, because the rays burn right through them and expose the whole gum  layer.  Here's a typical negative used to print gum with a medium pigment concentration (so not a high DMax).  You may not be able to tell it from the jpeg, but these negatives are so thin I can't tell, just holding them up and looking at them, what the image is; I have to put them in front of a white background to see what they are.  We're talking REAL thin.  I've learned to write the name of the image on the margin of the film, so I don't have to go find a white background to determine that I've got the right negative.   You may have seen this before, but maybe not, because I don't think I've got it linked to anything, I just stuck it up there one day to illustrate a point I was making on the list.


And yes, you don't want to move the tones up the wedge; that just means you have to develop longer to open the shadows, but it sounds like you've figured that out already.

Maybe it's the Everclear going to my head, but if the DR 2.0 negative printed for 2.5 minutes,  then it makes sense, doesn't it, that a thinner negative printed for 3.5 minutes would be overexposed?  I hope my instructions didn't get you off track; if so I may need to look at that page again. The point I was trying to make there was that if you expose for DMax alone, you're going to underexpose for gum, because you'll get DMax before you get the optimum number of steps retained, but obviously you don't want to take that too far.  If you settle on a standard development time it shouldn't take more than a couple of wedges to nail that down.


On Jul 21, 2009, at 8:46 PM, Paul Viapiano wrote:

Hmmm...ok, I see that. I just brushed some out of my pigment/gum mix and can see that it should be a bright sunny yellow, of course.

For my  testing I was using info on your site, re exposure, but I think I'm not understanding it correctly. You say that you should expose the test strip for the max amount of steps remaining after development, and I keep pushing exposure to move tone up the wedge, which I can see is wrong. But...hmm. In your reply, you mention using a fairly contrasty neg at under a minute in the sun...dang! I was originally using my digi-palladium negs which are approx DR 2.0 or slightly higher at 2 1/2 minutes, but the results were light, light, light ( http://www.flickr.com/photos/viapiano/3718825618/) with little contrast...so this is the stuff that stumps me.


----- Original Message ----- From: "Katharine Thayer" <kthayer@pacifier.com>
To: <alt-photo-process-l@usask.ca>
Sent: Tuesday, July 21, 2009 7:53 PM
Subject: Re: another 3 layer gum attempt

Wow, if that's cadmium yellow light, then it's way overexposed; I've
never seen a pale yellow do that before.  Caveat: I haven't worked
with cadmiums much except for test prints, as I find them too opaque
for my taste, but it didn't do that on the test prints I made with
it.  I'd say try cutting the exposure in half.  My sun exposures with
a black (fairly contrasty) negative  tend to be under a minute.

I agree that it's more likely overexposure than staining; that
doesn't look like stain to me.


On Jul 21, 2009, at 7:31 PM, Paul Viapiano wrote:

Much thanks Joseph and Katharine...!!!

I'll study your replies and reflect on what I need to do next.

Pigment is WN Cad Yellow Pale - PY 35
Concentration is 1 gram pigment to 9ml gum
Using .75ml of that mixture to 1ml potassium dichromate (for a 4x5  print)
Sun exposure for 3 1/2 minutes
Clearing 20-25 minutes
Fabriano EW unsized for this first layer

I can print white highlights unsized. I've done it in other prints,  so I think it's overexposure, not staining.

Your advice at least gives me a better grounding of what I need to  look for, etc and is so-o-o very helpful!


----- Original Message ----- From: "Joseph Smigiel" <jsmigiel@net- link.net>
To: <alt-photo-process-l@usask.ca>
Sent: Tuesday, July 21, 2009 7:14 PM
Subject: Re: another 3 layer gum attempt


I would say your exposure is way too long or you have severe staining
going on, or a combination of the two.  I'm basing this on the sort
of burnt mustard color of the border and some parts of the image, and
the fact that even the bright highlight on the nose has printed with
considerable density (or is heavily stained).  That area should print
paper white or very close to it.  Something (overexposure, staining)
has turned the highlights into midtones.  I suspect the negative will
print OK though it seems a bit on the contrasty side to me.

What is your pigment, concentration, exposure, etc.


On Jul 21, 2009, at 9:23 PM, Paul Viapiano wrote:

Ha!!  I needed to laugh...believe me...

Here is a combination of photo-negative-print that I was working  on today. Trying to dial in my negative, exposure, etc...you know  the drill.

What I would love is some feedback at this point, as I feel I'm   flying blind after trying several tricolor gums that always turn   out too light. I've made some adjustments to the neg, etc and  here  is what I have right now.


The neg is Blue (printing Yellow)...please feel free to comment  on  the density of the neg, the "look" of the Yellow print, or  anything  else that catches your eye. Am I on the right track or  does  somethng look terribly wrong here? I mean, I really don't  know what  the yellow layer should look like re: contrast, density...

Much thanks in advance for your observations...now back to the  Scotch!


----- Original Message ----- From: "Katharine Thayer" <kthayer@pacifier.com>
To: <alt-photo-process-l@usask.ca>
Sent: Tuesday, July 21, 2009 5:17 PM
Subject: Re: another 3 layer gum attempt

This is what the Everclear is for.

On Jul 21, 2009, at 5:05 PM, Marek Matusz wrote:

The suggested order would be
1. Procure the bottle of whatever liquor
2. Start drinking
3. Expose test wedge
4. Keep developing your gum test and keep drinking
5. When the bottle is finished you should examine test prin
6. All of the sudden it will all be clear, even if for a brief  moment

> Date: Tue, 21 Jul 2009 17:27:42 -0600
> From: kerik@kerik.com
> Subject: RE: another 3 layer gum attempt
> To: alt-photo-process-l@usask.ca
> Just don't drink the dichromate.
> I recommend Lagavullin.
> Kerik
> > -----Original Message-----
> > From: Paul Viapiano [mailto:viapiano@pacbell.net]
> > Sent: Tuesday, July 21, 2009 3:37 PM
> > To: alt-photo-process-l@usask.ca
> > Subject: Re: another 3 layer gum attempt
> >
> > (light bulb!! ding!)
> >
> > ok, ok...I have finally come to the realization that gum will
> > drive you to drink!
> >
> >
> > Paul
> >

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