Can anyone help me make emulsion without gelatine?

PeterWalsh

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Hello, I posted this as my introduction to Photrio but I am reposting here in case anyone can advise.

My name is Peter. I am a newcomer and beginner trying to make a Chloro-Bromide projection paper emulsion using a recipe from Denise Ross' wonderful book 'The Light Farm'.
I am substituting the gleatine with PVOH, sometimes also mixing in PVA.
My watercolour paper is subbed with PVA, but still my emulsion wants to dissolve in processing (even if I leave out the stop).
Where I have got an image, the finished product is 'Slow, fragile and has a short life' just as Ilford said it would be.
I've tried adding talc, cornflour, agar agar at various stages.
Any leads would be gratefully appreciated!
Thank you in advance.
 

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nmp

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Have you seen this work? It's POP, print-out process, but might be helpful for your develop-out paper:

PVAc POP

groups.io

:Niranjan

P.S. Welcome to Photrio!
 
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PeterWalsh

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Hi Niranjan, Thank you for the link. I see he stirs for a lot longer than me which is helpful. The link also led me to find PE talking about Mark Ostermann and PVA, also very helpful and new ideas to try.
All the best, Peter
 

Donald Qualls

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Are you avoiding gelatin to avoid animal products, or for some other reason? There may be synthetic products that are more like gelatin than PVA or PVOH, or it may be possible to harden agar enough to work the way gelatin normally would.
 
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PeterWalsh

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Hi Donald,

Yes, I don't want to use animal products, but I'm also fascinated with the idea of an alternative to gelatine. I don't know of any other products to try. What would you use to harden agar? Do you mean to increase the viscosity?

The emulsions I have made have been quite runny and are hard to coat using a coating bar or well, so thicker would be and advantage for that reason alone.

Many thanks, Peter
 

nmp

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Another one of Jim Patterson's processes uses sodium alginate (from kelp.)

Kelp Carbon

groups.io

Kelp carbon process – A direct positive carbon photographic process – AlternativePhotography.com

www.alternativephotography.com

Might get some more ideas...


:Niranjan
 
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PeterWalsh

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nmp

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One of the fortuitous properties of gelatin that makes it perfect for photo emulsions is that it is insoluble, but swellable at room temperature and soluble at higher temperature. So emulsion can be prepared and applied at temperatures above room temperature but it sets on cool down. During processing, it swells again allowing the chemistry to go in and out without itself falling apart and washing away. So the replacement would have to have this critical property. Gum is soluble at room temperature so it would do the same thing as what you are seeing with PVOH. I would say PVOH might still have potential if you play around with the molecular weight and the hydrolysis percent. Particularly look for a grade that requires heat to dissolve.

:Niranjan.
 
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PeterWalsh

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Thanks Niranjan,
I was drawn to PVOH because KODAK patented so many unused formulas featuring it. I didn't realise there were grades that reacted differently to temperature.
 

nmp

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PeterWalsh said:
Thanks Niranjan,
I was drawn to PVOH because KODAK patented so many unused formulas featuring it. I didn't realise there were grades that reacted differently to temperature.
Click to expand...

Welcome.

PVOH grades are specified as xx-yy where xx is the viscosity of 4% solution and yy is the percent hydrolysis (acetate to alcohol.) For example this one is 30-99 which is a medium viscosity but requires hot water to dissolve:

Polyvinyl Alcohol PVOH30-99 (Elvanol 71-30)

Science Kit Store provides scientific laboratory equipment and supplies for research and educational purposes to schools, universities, industrial labs and more.
sciencekitstore.com

Whereas this one is almost the same viscosity but may require cool to warm water:

Polyvinyl Alcohol Grade 25-88

Science Kit Store provides scientific laboratory equipment and supplies for research and educational purposes to schools, universities, industrial labs and more.
sciencekitstore.com

You probably want something that is difficult to dissolve at room temperature but not so much so that it becomes imperviously hard when dry which will hinder wet chemistry.

:Niranjan
 

Andrew O'Neill

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PeterWalsh said:
Hi Andrew,
Have you used Agar as an alternative to gelatine?
Thanks, Peter
Click to expand...

Yes, I have. I wasn't fond of it as I had setting issues... and more expensive than gelatine. I managed to make one print though.
 

nmp

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Oh and another idea I have is what if you treat your current PVOH emulsion with borax (essentially making slime) would it stabilize it for wet processing. Perhaps even add it to the developer. Just a thought...don't know what it would do to the other aspect of the process, though.

:Niranjan.
 
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PeterWalsh

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Hi Niranjan,
I didn't know that PVOH and now I'm wondering about the viscosity and hydrolysis of the compound I bought. Will find out when I get back to the darkroom. Yes, I think it would be an advantage to have something not dissolve at room temperature. Will try the borax idea too. What brought borax to mind? Have you used it in processing?
Many thanks, Peter
 
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PeterWalsh

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Andrew O'Neill said:
Yes, I have. I wasn't fond of it as I had setting issues... and more expensive than gelatine. I managed to make one print though.
Click to expand...

Hi Andrew, Did you coat paper with the Agar emulsion? May I ask what you used to coat the paper? Was it much thinner than gelatine? What was the print like and was it just one print out of many attempts?
Sorry so many questions!
 

koraks

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I know at least one major manufacturer of photographic emulsions has experimented successfully with gelatin-free emulsions. It can be done, but I don't know what materials they used for the successful tests. It hasn't gone into production because it was really hard/impossible to beat the relatively low cost of gelatin.

Peter, keep in mind Andrew is talking about carbon transfer prints. Those work fundamentally differently from silver halide emulsions. I'm not sure to what extent Andrew's experience with agar-based carbon (or kelp carbon, gum etc.) can be extrapolated to silver halide emulsions. While some of the material properties of the colloid used overlap for both process families, the inner workings are really radically different.
 

Kino

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Take it for what it's worth and I have no further information, but you might be able to dig something up:



"Cassell's Cyclopaedia of Photography, Edited by Bernard E. Jones. (1911), reprinted by Arno Press, 1973.

I do know that Logwood is available on many sites as a dye-stuff for cloth, so it's available...

EDIT: Ooops, thought you might have posted this to avoid using animal-based gelatin, but I appear to be mistaken. I'll leave it up in case anyone else finds it interesting. Apologies!

In any event, the book title is a link to an online scanned version of the original book which as a huge amount of information on printing processes. You might find your answers there! Good luck.
 
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Andrew O'Neill

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PeterWalsh said:
Hi Andrew, Did you coat paper with the Agar emulsion? May I ask what you used to coat the paper? Was it much thinner than gelatine? What was the print like and was it just one print out of many attempts?
Sorry so many questions!
Click to expand...

I size with acrylic medium. I got decent transfers after a few attempts, although I had to make a few adjustments to my workflow, such as mating the exposed tissue and substrate as soon as I put them in the water, gently squeegeeing, processing right away (mate no wait method) in cold water. Then develop in warm water... Sorry, I can't remember the exact temp but not hot like when gelatin is used. The prints were tonally nice but with zero relief. Zero. I quickly went back to gelatin.
 

nmp

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PVOH looks simple but there is a lot of polymer chemistry going on in there. Extent of hydrolysis and molecular weight both determine the viscosity and solubility behavior of the product.

PeterWalsh said:
Will try the borax idea too. What brought borax to mind? Have you used it in processing?
Many thanks, Peter
Click to expand...

PVOH-borax interaction is the principle behind the well known "slime" making that kids are very familiar with. Some time ago I was trying to see if it could be used make a sizing that is both insoluble and hydrophilic unlike say, PVAc based sizes which when set become plastic-like hydrophobic surfaces. The idea is to coat the paper with soluble PVOH, like the Elmer's Washable Clear Glue (which by the way is super convenient source of soluble PVOH.) Then treat it with dilute solution of borax which will form an insoluble film. For example, I added some India ink to EWCG and painted it on a strip of paper, dried. Then dunked half of it in 1% borax for a couple of minutes. Then washed it for several minutes. As can be seen below, the portion that was treated with borax remains untouched and the untreated side cleared out completely, save for a little stain.



So my thinking was since the developer is generally alkaline, small amount of borax wouldn't hurt it but could harden the binder. Alternatively, the paper can be pre-treated with borax solution before putting it in the developer. I don't know what happens in the stop bath - does it undo borax? Need to experiment as with all great ideas and alternative processes.

:Niranjan.
 
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PeterWalsh

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Hi Koraks,
That is so intriguing! Thanks for letting me know, and also for reminding me I might be going down the wrong road with carbon transfer. Yes, it's really silver halide emulsions I'm interested in. It's good to know it's possible, and that even gelatin might be replaceable.
 
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PeterWalsh

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Ha yes, thanks for all the extra details. Much appreciated.
 
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PeterWalsh

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Hi Kino,

You are right, I am trying to avoid animal-based gelatin. Thank you for the extract, ... 'logwood will precipitate gelatine' ! I don't understand how but I love that idea. Another one on my list to invgestigate.
 
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