The Fish Gelatin process - first CMYK prints

[Dan Pavel]

Thank you all!

Dan,

Did you size the paper. What type of paper if I may ask?

The paper used here is hot-pressed Fabriano Artistico Extra White 640. It needed to be pre-acidified in order to be used with Pt/Pd (the black layer). I have also tested Arches Platine 320 and it works as well.
Yes, the paper is gelatin-sized (normal gelatin) after the first layer(pt/pd black) is developed. I have tested sizing with Gamblin PVA and it didn't work for me.

 

[ced]

Dan love your print! How to improve the light tones, is it a question of curve adjustment on the negative or is this a process issue that cannot be resolved?

 

[Dan Pavel]

Thanks Ced!

If you refer to the stains in highlights that was a major problem for a long time. I tried all sorts of water-based colors: paste aquarelle, solid aquarelle, liquid aquarelle, gouache... All produced more or less stained highlights. I gave-up a few times and started it over again. Until, by chance(I was short of an aquarelle color), I tried some powder pigments and, for the first time, I had clear highlights. Probably is something in the color binders that makes a FAC-sensitized emulsion stain. An inter-layer of 1/10-1/12 diluted FG (unsensitized) helps, as well.

The powder pigments came with other issues: small dots of pigment in the light tones. Therefore I made a diluted solution of pigment in water, as suggested by Koraks, and filtered the solution heavily(3 times with different filters, the last being a lab-grade paper-filter). This solved the problem.

Just as with gum prints, I had some specks in the light tones. To remove them is one of the reasons why I am using 2 layers/color. Another thing that helped was to make the emulsion and let it rest at least 2 hours before applying it on paper. Using only moderate agitation during developing helps, as well.

If you refer to the color balance in the highlights I tried to solve that by using a balanced amount of the 3 pigments so that when mixed in a diluted solution a neutral grey will result. For instance, if 4 drops of Y, 4 drops of C and 5 drops of M give a neutral tonality then the ratio of pigment quantities to make the same amount of C, Y and M emulsions will be 4, 4 and 5. Then I could use the same curve for the 3 colors.

Of course nothing is perfect, but I am not trying to compete with prints made with inkjet printers, for instance. All I want is to have a CHIBA process that can give reliable, reasonably repeatable results with a specific look for my prints.

I have noticed a particularity of the RGB to CMYK conversion in PS: not all of a neutral tone is translated into the black channel and some of it is made of a mix C, M and Y. This has very little impact in the shadows and mid-tones of a print but makes the highlights very sensible to any tiny color misbalance. That's why I try now in PS to treat the highlights different in my new print and increase the K part of the highlights while decreasing the CMY part. But that's a work in progress...

 

[koraks]

have noticed a particularity of the RGB to CMYK conversion in PS: not all of a neutral tone is translated into the black channel and some of it is made of a mix C, M and Y.

There are several ways in which the K channel is abstracted from the color channels. There are a few Wiki pages on these differences. I've never seen this topic discussed in the alt process printing community even though it's quite pertinent. I'm not sure what controls PS has for this aspect. Maybe there's a way to control this.

 

[PGum]

Thank you all!


The paper used here is hot-pressed Fabriano Artistico Extra White 640. It needed to be pre-acidified in order to be used with Pt/Pd (the black layer). I have also tested Arches Platine 320 and it works as well.
Yes, the paper is gelatin-sized (normal gelatin) after the first layer(pt/pd black) is developed. I have tested sizing with Gamblin PVA and it didn't work for me.

I have never been a fan of Gamblin PVA with this process. I think it weakens adhesion, so there is more breakup in the mid-tones. At least that has been my experience.

 

[FotoD]

I have never been a fan of Gamblin PVA with this process. I think it weakens adhesion, so there is more breakup in the mid-tones. At least that has been my experience.

I agree. I think the the difference in adhesion between hardened and unhardened fish glue is too low with PVA sizing.

 

[NedL]

Dan, just to clarify.. this is fish gelatin and not isinglass, correct? Isinglass is a particular kind of fish gelatin/glue from swim bladders, ... I think generic "fish gelatin" can come from lots of different kinds of fish and usually from the skin....

Sounds like it works really well with FAC.

 

[koraks]

Dan, just to clarify.. this is fish gelatin and not isinglass, correct? Isinglass is a particular kind of fish gelatin/glue from swim bladders, ... I think generic "fish gelatin" can come from lots of different kinds of fish and usually from the skin....

I stand corrected; I did not realize this!

 

[Dan Pavel]

What I use is a fish glue solution sold by Kremer. It is made of fish skin and is, in fact, an approx 45 % solution of fish skin gelatin in water. Small amounts of sassafras are added to improve fragrance.

The technical data-sheet:

63550 Fish Glue

Fish glue is a highly viscous liquid at room temperature. If further thickens when cooled down, by minus degrees it
reaches a rubber-like consistency. Fish glue can be made liquid again by heating without any loss of quality. Fish glue
is a natural product which is obtained by cooking fish skin, followed by evaporation.

Physical and Chemical Properties
Color: Light caramel
Temperature range: -30°F to +500°F
Solid content: approx 45 %
Water content: approx. 55 %
Viscosity at 24°C: 4000 cps
Average molecular weight: 60,000
Melting point: 5 - 10°C
Ash: Less than 0.1%
pH-Value: 4 – 6
Specific gravity (20°C): 1.17 g/cm3
Time to tack: 1 Minute
Open time: 1.5 to 2 hours
Storability: Excellent (freeze-thaw stable)
Flammability: Non-flammable
Shear strength: 3200 PSI with 50 % wood failure (ASTM D 905)
The viscosity is measured at 24°C with a model LVT Brookfield Viscometer 4°C. This method uses a rotating spindle
inserted into the liquid.
No gel-depressants are added. Small amounts of sassafras are added to improve fragrance.

Application Methods
Surface may be coated by roller coat, knife coat or brush coat.

Applications
1. As an additive to adhesive formulations in the manufacture of remoistenable gummed paper packaging tapes.
2. Wood gluing when long open times are needed for assembly operations.
3. Paper bonding of heavy grade box board in packaging.
4. Bonding of manila paper for identification tag manufacturing.
5. As a water based leather finish.
6. Any application where it is desirable to supply an adhesive coated surface which is to be re-activated much
later by simple water remoistening.

Advantages
1. High initial tack when first coated or when remoistening the dry adhesive film.
2. Slow setting for wood bonding applications when open times are desirable.
3. Good solvent resistance.
4. Excellent heat resistance.
5. Easily thinned and cleaned up with water.

Properties
An organic fish glue with high initial tackiness. Once coated and allowed to dry, fish glue has excellent remoistening
properties. This allows for easy re-activation of adhesive by water at a later time for bonding. Fish glue has good
solvent and heat resistance but poor water resistance.

Cold Bonding
While adhesive films are still wet materials should be bonded and maintained under pressure until adhesive sets.
Suggested clamping time for wood, 12 hours.

Re-activation
Surfaces coated with fish glue and allowed to dry may be readily re-activated by a light coat of water. The remoistened
surface develops immediate tack and may be bonded to many surfaces including steel, glass and wood.

Adhesive Additive
Gummed paper tape: It is recommended that 10% be added to the basic adhesive formulation to obtain maximum tack
retention and cold water remoistening properties. A 5% addition should be a minimum recommendation.

Leather Finishing
Fish glue has very high leather pigment suspending power, good gloss and excellent heat resistance. A small addition to
leather finishing solutions, depending on the formulation, is all that is required.

Solvents
Thinning: water
Clean up: water

Shelf-life:
Approx. 10 years after packing date.

 

[Dan Pavel]

It looks like in 1915, in Vienna, Heinrich Kühn developed a fish gelatin printing process. I couldn't find any details about the process or any images of printings using it. Does anybody have more info about it?

 

[FotoD]

Leimdruck. He became a nazi later in life. There are some images on the web, I'm pretty sure a few of them are Leimdrucks, but most are gum prints and other processes.

By the way, how is the writeup coming along? It'll be interresting to see what has worked for you. (I'm especially hoping you'd show a print of a step wedge with a single color layer.)

 

[Dan Pavel]

That a how step wedge (not final) looks like:View attachment 399023

But it has 2 color layers...

 

[FotoD]

Thanks!

The transition between the layers looks nice and smooth.

Is it 0.1 density between the steps?

 

[PGum]

That is a very clean tonal scale, congrats. The two exposure layers approach seems to do a great job.

The fish glue that I had worked with in the past was from Lee Valley Tools. Properties seem almost indentical. What can I add: FG seems to be mostly preserved with phenol. I was able to dilute mine to 50/50 for a final 22.5% soln for a more workable viscosity and it still did not go off at 2yrs storage. If stored at this dilution the opacifying agent will eventually settle out after about 6 mos to a year, and it goes very transparent. It is some kind of pigment possibly TiO2. It aids the application for gluing, allowing better visibility. No effect on prints. It is just too little to be concerned about in thin coats for printmaking. Diluting further will weaken the preservative action and it will go off.

 

[Dan Pavel]

Is it 0.1 density between the steps?

I divided the max. value of 255 into 48 steps with a general difference of 5 and some with a difference of 6 between them.

 

[NedL]

Thank you for the information! It is available directly from the Kremer website, with flat rate $12 shipping to US. Now it's on my "todo" list because I'd love to be able to make more robust gelatin relief with FAC and/or FAO for several processes. I suspect if I try your "direct carbon" process with it, it will probably only be with lampblack or ivory black.... but those could be very nice.

Made me chuckle that they add sassafras!

I think there was an isinglass calotype process that I don't remember much about and have not tried. My ( possibly faulty! ) memory is that it help improve keeping quality in some way. It used real insinglass.

 

[Dan Pavel]

My second fish gelatin print:

Summer Memories​

Here I replaced some of the CMY grey with K grey by using the PS tools. My conclusion is that the idea is good but it can't be properly applied by using PS only (or I don't know how to do it properly in PS). I've started to write a little program to do it.
It was not an easy print because the FAC was over and I had to replace it with a newly prepared one after the yellow layers. The new FAC acted a bit different and I had to help a bit the development on some regions with a very soft brush. I have ordered a larger quantity of FAC and probably I'll need to change a little the curves to accommodate the new sensitizer.

 

[PGum]

The new FAC acted a bit different

That is a great looking print too. Congrats!

My first suspicion is that the pH of the FAC may be the issue. FAC has no precise chemical composition in terms of the ratios of iron, ammonia, and citrate. Hence, the final pH may differ by manufacturer. The effect on fish glue prints is to change the contrast. A shorter scale and faster exposure indicates a lower pH. A pH paper in the range of 4 to 7 would be helpful for testing. If you have some of your old stock left, then compare. You can always tweak the pH to where you want it.

 

[Raghu Kuvempunagar]

My first suspicion is that the pH of the FAC may be the issue. FAC has no precise chemical composition in terms of the ratios of iron, ammonia, and citrate. Hence, the final pH may differ by manufacturer. The effect on fish glue prints is to change the contrast. A shorter scale and faster exposure indicates a lower pH.

Would a FAC substitute like the one used in Mike Ware's Simple Cyanotype be useful in processes such as this? The substitute has some Ammonium Nitrate in it though.

 

[joho]

Finally, after more than 1 year of testing, I have managed to tune the process and start printing. Here is the first print.

View attachment 398049

The process involves using Ferric Ammonium Citrate to sensitize a pigmented fish gelatin solution. The development is done in a diluted solution of peroxide.
It is a perfectly harmless alternative for gum printing and therefore an airbrush can be used to apply the solution on paper. That's what I did.
This print is a 6 layers CMY fish gelatin print on a Pt/Pd black layer. The paper used here is a 280x380 mm. sheet of Fabriano Artistico 640.

The process itself involves more stages and precautions and therefore I'll write a detailed presentation later, next week. Till then I work on a new print.

I am at a loss , did you hand color the [Ferric Ammonium Citrate to sensitize a pigmented fish gelatin solution] -- made a caynotype ??????????

 

[koraks]

I am at a loss , did you hand color the [Ferric Ammonium Citrate to sensitize a pigmented fish gelatin solution] -- made a caynotype ??????????

He created a multi-layer pigment print, with separate layers for C, M and Y, based on color separations produced on (I suppose) Photoshop. These pigment print layers were made with fish gelatin and a suitable pigment, i.e. different pigments for cyan, magenta and yellow. He also used a K (black) layer; for this he didn't use a fish gelatin/pigment print, but instead used a Pt/Pd print as it's quite neutral black. So you're effectively looking at four prints stacked on top of each other: a Pt/Pd monochrome print, and then C, M and Y pigment prints on top of that. The same image has been printed four times, through four different negatives, and each negative was extracted from the same original (digital) color image.

This approach is conceptually similar to how full-color gym bichromate or carbon transfer prints are being made. It also bears similarity to other subtractive color printing processes, including inkjet, dye transfer, offset printing etc. etc. etc in the sense that these all rely on overlaying different color layers.

Hope this helps.

 

[Dan Pavel]

Would a FAC substitute like the one used in Mike Ware's Simple Cyanotype be useful in processes such as this? The substitute has some Ammonium Nitrate in it though.

That's an interesting question. If it works it could be an improvement.
I have already ordered the necessary chemicals and I'll definitely test it when they arrive.

 

[Duboscq159]

- Ignore if your aware already - Some contemporary work related to Kuhn's Leimdruck see/search Chiba Leimdruck and Charles Guerin.

 

[Carnie Bob]

He created a multi-layer pigment print, with separate layers for C, M and Y, based on color separations produced on (I suppose) Photoshop. These pigment print layers were made with fish gelatin and a suitable pigment, i.e. different pigments for cyan, magenta and yellow. He also used a K (black) layer; for this he didn't use a fish gelatin/pigment print, but instead used a Pt/Pd print as it's quite neutral black. So you're effectively looking at four prints stacked on top of each other: a Pt/Pd monochrome print, and then C, M and Y pigment prints on top of that. The same image has been printed four times, through four different negatives, and each negative was extracted from the same original (digital) color image.

This approach is conceptually similar to how full-color gym bichromate or carbon transfer prints are being made. It also bears similarity to other subtractive color printing processes, including inkjet, dye transfer, offset printing etc. etc. etc in the sense that these all rely on overlaying different color layers.

Hope this helps.

I. agree, this process looks and feels a lot like my own work with gum coloured layers over palladium or cyanotype. This summer I have invited Peter Schrager to show me his method of hand coating silver which I will then add layers of colour on top

 

[Raghu Kuvempunagar]

method of hand coating silver which I will then add layers of colour on top

Bob, wouldn't the dichromate in the gum layer harm the silver? Are you going to gold tone the POP print before the gum layer?