I have an old box of Knox Gelatine (pic enclosed)

[Photo Engineer]

Actually, I used the 'old' stuff to make a gelatin cyanotype, it turned out beautiful. It was on the same Fabriano paper I am having so much trouble getting my silver gelatin emulsion to stick to. Which make me want to give this paper a sub coat of Knox before coating the silver gelatin.

PE, do you think this box of Knox is an active gelatin?

Cyanotypes are insensitive to the ingredients in gelatin that make it act on Silver halides. Just about any kind of gelatin will work on many alternate light sensitive systems.

I can't tell if this is active, but I would guess that it is. After all, why go through the expensive and lengthy oxidation and extraction process to make it inactive, when the active gelatin is harmless to humans?

PE

[Kirk Keyes]

PE, do you think this box of Knox is an active gelatin?

If it's not made for photographic use, there is no reason to purify it so that it's not active.

[tim_bessell]

Kirk,
Didn't you mean 'there is no reason to purify it so that it's not (IN)active.'
Sorry Kirk, i think i get it now, it getting late in the day for me.

PE,
Photograde gelatin doesn't work with cyanotype for me, don't know why, just don't look good like Knox.

A friend of mine lives much closer to Buffalo than Rochester. A few years ago they changed his area code to 585, now all the calls he makes are long distance. Way to go Ma Bell!

T

[Photo Engineer]

Probably the Bloom Index but IDK really why photograde does not work with Cyanotype. It does for me.

PE

[wildbillbugman]

I spent the first 26 years of my life in NYC. Nobody I knew had an address or phone number! Stange, is it not?
Bill

[Kirk Keyes]

Kirk,
Didn't you mean 'there is no reason to purify it so that it's not (IN)active.'
Sorry Kirk, i think i get it now, it getting late in the day for me.

Ummmm - let's see, I think there were too many negatives in my statement to make it understandable... Let's try again -

"If it's made for food use, there is no reason to purify it so that it's inactive."

I hope that is better -

Anyway, just what PE said. (Plus he beat me to that post by 1 minute and with much more clear language.)