Gesso Prints?

[Allen Friday]

Wednesday afternoon is normally my time to play golf. It was cold and raining yesterday, so I decided to stay indoors and play in the darkroom instead. I was working on gum over platinum when I came across a bottle of gesso sitting on my storage shelf. This got me thinking. Gesso is water soluble and used for sizing. I wondered if I could make a print by substituting gesso for gum. I played around for a few hours and made a few prints.

I used Luquitex Clear Gesso. 5 ml gesso, 5 ml water, 5 ml ammonium dichromate saturated solution and .5 grams gum pigment. The results were somewhat interesting. I attached one of the prints below. The negative prints well on a midrange platinum mixture and on the newer grade two Azo. The negative is too long scale for the process, but worked for an experiment. The scan shows more texture than the print.

I checked my alt. process books and I googled gesso and as many variations on it as I could think of, and didn’t come up with any references to anyone actually making gesso prints. I would like to pursue this sometime, but I don’t want to reinvent the wheel. Has anyone here made gesso prints or does anyone have a reference to using gesso instead of gum in prints?

I don’t know that this will actually lead to anything terribly useful for photographic purposes, but it is fun to play around with. Any help is appreciated.

Allen

 

[Whiteymorange]

Very interesting. I've never heard of Clear Gesso, but I assume it's basically matt acrylic medium. In printmaking "back when" we used to make photographic etchings by using Elmers glue and bichromate (ammonium or potassium, whichever we had) for a resist on the zinc plate. The process was a bit basic, but it worked. I suspect any clear material that will stick to the paper might work if sensitized and exposed, but I'll let more accomplished printers weigh in on that one. Nice work.

 

[John Kasaian]

Neat! I like it

 

[Katharine Thayer]

Allen, this is very interesting, since it "shouldn't" work, but obviously it does.

The crucial kind of water-solubility for gum printing is not whether the liquid material can be mixed with water, but whether a thin layer of the material, brushed on paper and dried, is then soluble in water. Technically, acrylic medium shouldn't qualify, because it should be insoluble when coated and dried, in fact if acrylic gesso were soluble in water once it was coated on the substrate and dried, it wouldn't make a very good ground for acrylic paints. The small amount that it's diluted shouldn't make it that much more soluble when dried; many people use acrylic medium as a sizing for gum diluted up to 1/10. So I don't know what the heck is going on, but it's very curious. It made me curious enough to think about ordering some clear gesso and trying it myself, but Daniel Smith, my catalog of choice, doesn't make a clear acrylic gesso.

Two questions: (1) I assume you did dry the coating before exposure? (I'm grasping at straws here, you can see) and (2) what kind of paper did you use, and did you size it with gelatin before coating with the gesso-dichromate?

Thanks for a very interesting post.
Katharine

 

[Allen Friday]

Katharine,

Thank you for your interesting post. When I started this experiment, I didn’t really think it would work. It was one of those “let’s see what happens if I do this” moments. My first print using straight gesso worked okay, but it was heavy, so I diluted the gesso with water 1 to 1 to make it coat more evenly.

I have now used 3 papers, Cranes Platinotype, Rives BFK and Artistico EW, scraps left over from my platinum and gum over printing. I find the Cranes paper terrible for gum overs, but it worked fine for this experiment. The print I posted was on Cranes.

I did not size the paper before coating. I also didn’t completely dry the emulsion before printing. The instructions on the bottle say to let the paper dry over night to be completely dry. I let the paper dry for a few minutes under a fan and then hit it with warm air from a hair dryer to make the top of the emulsion dry to the touch. Printing times are very long, up to 2 hours. I developed in warm water for 5 to ten minutes.

After reading your post, I wondered if a fully dried paper would work. I had a corner of the paper used for the print in the first post left over. It sat for two days in file cabinet. I just exposed it and got an image. I only exposed it for about 15 minutes, just to see if it would work at all. There is an image there. This all has me stumped.

Now for some more fun, another method that shouldn’t work. Last night I tried Liquitex Gloss Medium and Varnish to make a print. I used 10 ml gloss, 10 ml dichromate and .5 grams acrylic paint. Attached is a scan of the print. I did not filter the emulsion and ended up with the dark “chunks” of paint on the print. Next time I’ll use less paint and filter before coating the paper.

I still don’t know if this play will lead anywhere productive, but it’s fun to experiment on breaks from serious printing. I was thinking this might be usable on very hard to coat surfaces. Perhaps a gesso over tintype?

 

[Katharine Thayer]

Well, hmmm.... that's really interesting, and you may have me stumped; I think maybe you've discovered something new. My first tentative hypothesis, before you responded, was that the gesso wasn't actually serving as a reactant but that the dichromate was reacting with either an applied sizing, or with an internal gelatin size. But that hypothesis would have worked better had you sized the paper or had you used a paper like Arches which uses an unhardened internal gelatin size, which could have reacted with the dichromate, leaving the gesso as a passive bystander, its transparency allowing the image to be visible and its porosity (as a polymer) freely allowing the unhardened gelatin/pigment to flow out. That was my hypothesis anyway. I don't know anything about the amount or type of internal sizing in the papers you mentioned, except that I rather doubt there's much if any in platinotype (I could be wrong about that of course) and that I know that the sizing in Fabriano Artistico EW is something other than gelatin, although I don't know if it would react in the same way as gelatin would. At any rate, my hypothesis didn't get a lot of support from your observations, and I'm not sure why I'm confusing the issue by sharing it now, except to show that I've been thinking about this.

I've tried mostly unsuccessfully to get much information about the constitution of the clear gesso; I surmise from a couple things I read that it is acrylic medium with something gritty in it, although I don't know what's gritty and transparent at the same time. Silica? But I would guess that it's a good clinger, and I agree with your surmise that it should be good on hard to coat surfaces. Carry on....
Katharine

 

[Allen Friday]

The bottle doesn't provide much help on the make up of clear gesso. The only thing it states is that the vehicle is "Acrylic Polymer Emulsion."

I'm done playing with this for a little while; I need to get my prints for the Alt. Print exchange finished and mailed. When I pick it back up, I may start printing step wedges and vary the amount and type of dicromate to see if I can't pick up the speed a little. (Although I hate printing step wedges.) I also need to see how this works printed over standard emulsions.

I just had an idea. I wonder if this would work over a silver print? I may have to give that a try this week end.

Thanks for your in put. Any ideas are most welcome.

Allen

 

[Struan Gray]

If you can find an MSDS (safety data sheet) for the gesso it will probably tell you what's in there.

My first thought is that you may just be modifying the acrylic with the UV, in which case it is possible the technique would work even without the bichromate. PMMA - generic "acrylic" - is a standard resist in the semiconductor industry, which can be exposed with UV light.

If that is what's happening, you may be able to speed up development, and perhaps get more control, by using a more polar solvent. Acetone or MEK (methyl ethyl ketone) are standard solvents for removing semiconductor resists, often diluted with isopropyl alcohol. Both solvents will rot your liver, so make sure you have good ventilation (and no naked flames).

 

[Allen Friday]

Struan,

I tried a print over the weekend using gesso and watercolor pigment only, no dichromate. No image at all, even after three hours under the light. So, the dichromate definately has an effect.

Thanks for the idea, however, it was certainly worth a try.

Allen

 

[Struan Gray]

Another beautiful theory ruined by an ugly fact

One clue: PMMA is a positive resist at low exposures, and only forms a negative once you expose enough to cross-link the polymer instead of depolymerising it. "Low" and "high" are quantified exhaustively in the literature, but it's not obvious (to me at least) how to relate those exposures to a typical alt-process exposure setup. In any case, the fact that you got a negative response suggests that the dichromate is promoting cross-linking right from the start.

I can ask around our resist experts here and see if anyone has tried to enhance resists with additional oxidisers. I'm sure someone has, but the results may have been so ugly that they never published