Fish gelatin can be used, I believe.
There is a company that sells it for use in photographic purposes. It will not chill set and therefore has not been used in main stream photo products.
Originally Posted by jnanian
You are probably thinking of blood-agar plates for microbiological cultures. If the test requires mammalian blood, sheep's blood is often the source. The agar part is an un-branched polysaccharide derived from seaweed IIRC. I also seem to remember that the medium didn't smell that great - especially when the used Petri dishes were autoclaved for reuse.
There was some discussion of "dichromated non-gum-arabic substances" on the alt-photo-process list in the past.
Agar-agar is mentioned here:
If you search the alt-photo-process archive you will find some discussion of various "dichromated colloids" which do not use gum arabic.
Hey John... I see you are in France you lucky dog!!... I'm still at the beach.
My weed trip....
From time to time I have been photographing the 'illuminated sea'... ( read that as... I stick my arm under the surface and blast off my Nikonos on the B setting... serendipity at it's finest!). You may recall my adventures with the arbutus tree and developing the images in the tannins derived from the subject... this is the same thing but with the ocean (rather like making a sculpture of Adam out of clay...the technology mirroring the metaphorical essence of the work!!!)
Anyway... after many observations of beach-cast weeds I have stumbled on a few that have made super coatings for my alt prints. The criteria for selection is quite simple... when you see them dried on the beach you grab the shiny ones... they are easily rehydrated and the 'gelatins' exctracted... don't do this by boiling or the gel will take up the color of the seaweed... magenta, brown, green. I have a coating that I am using now that has a nice gloss... think of the lickey bit on an envelope.
It is also interesting that conservators are starting to use fucoids (these gels are pure and clear) for restoration of art pieces where paint is flaking... they are archival and under simulated time testing they do not yellow.
Clarence... thanks for the link... it has me thinking about the possibility of a new gum-over.
Cheers all... Annie
cold setting of fish gelatines
pe-i have seen fish gelatine cold set in the food prep trade-depends on the fish-this can be an intended and desirable end product-it can be a frustrating and undesireable consequence in cebeche fish prep
Originally Posted by Photo Engineer
agar as a size was in use back in the day, and is in use right now in some processes, i was surprized to find out recently
the successful ongoing use of culinary gelatine, in some cases supermarket knox, by holo plate makers gives 'food for thought'
vaya con dios