U of S | Mailing List Archive | alt-photo-process-l | Re: Single coat gums

Re: Single coat gums



Hmm, this is interesting; I wish we could see the illustrations. If I'm reading the instructions correctly, the intent here isn't to use a very heavy pigment mix, as I thought it was with Zimmerman. These authors emphasize that beginners often overestimate how much pigment is needed, and that "In working with gum prints, one is more and more surprised at the small amount of pigment required to make a strong print." So I don't get the idea that they are advocating making a very pigment-heavy mix, but I could be wrong.

I remember studying the Zimmerman article on the B&S website, but I don't remember whether I ever tried it. However, I did try the method mentioned in the Demachy and what's his name article that, like the article John has quoted here (thanks!) called for soaking the paper in potassium dichromate (10% in their case) and drying it, and then brushing it with a heavy mix of gum and pigment. My experiment with this was not a success; there are a couple of examples on this page, along with the same negative printed the normal way.

http://www.pacifier.com/~kthayer/html/Demachy.html

When I reported my failure to the list, someone suggested that I might have better luck if I would try sizing with gelatin and cornstarch, so I tried that (included on the page) but that didn't work any better. The main problems I had were (1) the heavy gum/ pigment mix tended to flake off, and (2) a very heavy brown dichromate stain. The dichromate stain could of course be cleared, but since I could get a better print without the dichromate stain printing my usual way, I wasn't tempted to pursue the method further.
Katharine


On May 19, 2007, at 1:00 PM, john@johnbrewerphotography.com wrote:

Hey Don and other gummists

While I don't have Mr Z's recipe I've found in the September 1921 issue of Camera Craft part two of an article called The Gum Process In Portraiture by Prof Daniel Cook with illustrations by Nancy Ford Cones. The recipe implies to me that it is a single coat process and I quite like the illustrations. Here's the recipe:

'The first step is to select a paper that has enough body to remain on the surface of the solutions. A paper that becomes saturated and sinks to the bottom of the tray is difficult very to handle, but the heavy grade of Whatman, and some imported papers, particularly the French charcoal, are very satisfactory. The next step is to prepare a solution of gum Arabic, 1 oz. to 3 ozs. of cold water, by placing in a muslin bag and suspending in a wide-mouth jar so the gum will be partly submerged. This solution will require about 30 hours to dissolve, and will be about the consistency of strained honey.

Next, a saturated solution of bichromate potassium is made, and is kept in a dark colored bottle, as this solution is sensitive to light. The paper is soaked in this solution until thoroughly limp, and then hung up to dry in a dark room. For the pigment, any dry color will do for a trial, black being easiest to work with. If moist water color is used, one should be sure that is has no oil, such as glycerine. Pigment is now gradually worked into the gum solution with a spatula until the proper amount of color is obtained. This will be the depth of the darkest shadows, a very interesting point.

A smooth board is next padded with several thicknesses of newspaper,a sheet of the sensitized paper is pinned on it, and with a bristle brush - about two inches is a good size - the color is quickly painted on the paper. One should try to cover the surface evenly at the first application, so that there will be no overlapping streaks, then one should immediately blend each way with a badger blender. When dry, the sheet is ready to print.

About the same exposure in bright sunlight is needed as required to print solio proof deep. In a tray with plenty of cold water, it is better to have it two or three inches deep, the exposed sheet is floated face down in the water, and as the bichromate dissolves out, the print is lifted carefully by one corner and allowed to drain for a few seconds so it will not stain. if the print has been properly timed, the outline should appear quite distinctly in about five or ten minutes. The paper should be left in the water until the image is fully developed. The time is usually from fifteen minutes to half an hour, although it is not absolutely necessary for the print to develop in such a short time. If it is over- exposed, the development can extend into hours and still make a good print, though of different quality. When dry, the print is more permanent than can be obtained by any other process.

The chief mistake with beginners is usually in coating the paper too heavily. In working with gum prints, one is more and more surprised at the small amount of pigment required to make a strong print. By practice one will be able to coat the paper to suit the negative. A very thin coating is required for a contrasty negative, while a flat, thin negative must have a heavier coating which will make a better balanced print."

Best

John.


www.johnbrewerphotography.com
----- Original Message ----- From: "Don Bryant" <dsbryant@bellsouth.net>
To: <alt-photo-process-l@usask.ca>
Sent: Saturday, May 19, 2007 12:46 AM
Subject: RE: Single coat gums



Hi Dick,

Any chance you guys can get the Zimmerman JPEG file back up on the B&S web
site? The current link is dead.

Thanks,

Don Bryant


-----Original Message-----
From: Richard Sullivan [mailto:richsul@earthlink.net]
Sent: Friday, May 18, 2007 7:38 PM
To: alt-photo-process-l@usask.ca
Subject: RE: Single coat gums

Talk about dredging up the past!

I had forgotten even doing that.

Now that I have worked with carbon for a few years I can see where Zimmerman
was coming from.

I think his process is similar to what we think the direct carbon process
was, and in specifics, the Arvel process. Christian Nze sent me a
translation of a formula for direct carbon a few years ago. Basically it was
a very thin tissue with very little gelatin and lots of pigment. Sounds a
lot like Z's method. I am not sure what the working model is for this just
yet. Like Jack Benny, I'm thinkin.

--Dick

-----Original Message-----
From: Don Bryant [mailto:dsbryant@bellsouth.net]
Sent: Thursday, May 17, 2007 1:02 PM
To: alt-photo-process-l@usask.ca
Subject: RE: Single coat gums

Hi John,

Thanks for the link but I was aware of his post. There once was a copy of a
file outlining the method on the B&S website, but it is gone now.

When the old B&S alt forum was still active I did see one individuals scans
of prints using this method. Very nice work, moody images printed with a
mixture of Paynes Grey and Ivory Black originally shot on Kodak HIE.
Thai person used the blotter technique and swore by it. His results seemed
to support his claims. Unfortunately that is the only instance I'm aware of.

Can blotter paper still be purchased?

Thanks,

Don



-----Original Message-----
From: john@johnbrewerphotography.com [mailto:john@johnbrewerphotography.com]

Sent: Thursday, May 17, 2007 2:42 PM
To: alt-photo-process-l@usask.ca
Subject: Re: Single coat gums

Hi Don

Dick Sullivan made a successful print,
http://www.usask.ca/lists/alt-photo-process/1998/alt98b/1875.html

Cheers

John

www.johnbrewerphotography.com
----- Original Message -----
From: "Don Bryant" <dsbryant@bellsouth.net>
To: <alt-photo-process-l@usask.ca>
Sent: Thursday, May 17, 2007 4:50 PM
Subject: Single coat gums



Okay, I have a question regarding single coat gum printing techniques.

Has anyone ever tried the Zimmerman method for single coat gum printing?
I've always been intrigued by the idea and wondered if it really worked.

I suppose I could try and find out but never the less I'm curious to
hear of anyone else's experience.

Thanks,

Don Bryant








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