Photographic gelatin

Joe Farina · Post by **Joe Farina** » Wed Jul 04, 2012 2:08 pm

I was reading a paper by August Muth and he said "The higher quality laboratory and photo gelatins will produce the cleanest images." I assume this is in comparison to grocery-store gelatin like Knox.

Someone on a forum (a photographic engineer, it seems) said that food grade gelatins contain a lot of extra ingredients, and that some might be only about 30% gelatin. It was an argument in favor of using photographic gelatin.

I was wondering if anyone can point me to a source of "photographic" gelatin. So far, I've found two, but the information they provide is minimal. One is from Silverprint in the UK (unknown bloom strength) and the other is from Photographer's Formulary (with a bloom of 250).

Kiffdino · Post by **Kiffdino** » Wed Jul 04, 2012 3:30 pm

that is very interesting. here in germany im getting prices for photo-gelatin around 16-18eur for 100g. thats 10times the price i pay for high grade food gelatin.#
on offer it says bloom 267. thats a little harder than what i use at the moment which is 230-240
love to read that paper from august muth.

Joe Farina · Post by **Joe Farina** » Thu Jul 05, 2012 5:58 am

This is a link to the discussion about gelatin:

http://www.apug.org/forums/forum205/311 ... types.html

holomaker · Post by **holomaker** » Thu Jul 05, 2012 6:09 am

ive always used Knox gelatin for my DCG, Baker sent me a large sample of 200 bloom strength, and aside from the replay color i didn’t see much difference, recently @ ISDH Auggie mentioned how clean my DCG hologram looked (and that was made only using Knox brand), personally for anyone getting started in dcg Knox is the best way to go, when you need to start to control colors (like 2 color DCG), a higher bloom will make things less difficult.

Thanks Joe for posting that link to the thread, but what i got out of it dosent really point me in any piticular way to decide if food type gelatin (knox) is better than the photographic grade gel ................

Johnfp · Post by **Johnfp** » Fri Jul 06, 2012 8:26 am

I did quite a bit of research on gelatin. One thing I found is that if you use Bone gelatin, which is common in the photo industry you have to be aware it contains traces of silver naturally from the bone. This may help silve halide film ( I think it gives a slight speed increase if memory serves me correctly) but I am unsure how it may affect DCG. Also, the most import thing I found about gelatin is having the same gelatin lot. That is, gelatin being made from animals can varry quite a bit from batch to batch. So if you are going to make a lot of your own plates you should buy a large batch of the stuff, enough to last you for years, and dial in the variables for that batch. While the KNOX is a great start I would imagine that they control quite a bit of the variables because it is being consumed.

Johnfp · Post by **Johnfp** » Fri Jul 06, 2012 8:31 am

I found one of the threads in the old forum.

http://holoforum.org/oldforum/viewtopic ... 441ca90cca

Joe Farina · Post by **Joe Farina** » Fri Jul 06, 2012 8:52 am

I've only used Knox for DCG, and the results have been good. But the comment by Muth and various statements in the papers suggest that laboratory or photographic-grade is better. The scuttlebutt on the internet seems to agree. Of course, only tests will tell.

Photographer's Forumulary gelatin is supposed to be Kodak photographic gelatin (bloom 250), at least according to someone who checked this with PF. The price for one pound (I think this would be around 450 grams) is $25, which would last a very long time.

But I have so far been unable to find out any other details about this gelatin, I assume it's bone gelatin (ossein)?

Johnfp · Post by **Johnfp** » Fri Jul 06, 2012 11:50 am

http://online.wsj.com/article/AP84cb61b ... aaecf.html

http://bridge2food.com/rousselot.asp

You may be able to call the later company which bought KODAK gelatin business and ask them for details.

Joe Farina · Post by **Joe Farina** » Fri Jul 06, 2012 12:13 pm

Thank you John, that is interesting. Rousselot has been around a long time. Too bad to see Kodak struggling though.

holomaker · Post by **holomaker** » Mon Jul 09, 2012 5:35 am

Joe i can send you a small batch of the 200 bloom baker if you would like test it out ? PM me your address if you want it ......................