Perhaps the most common measure of degree of hardening is swelling
factor. Unhardened gelatin swells many times the dry thickness when
soaked in water at 20C. For pictorial silver gelatin films, major
manufacturers (Fuji, Kodak and Konica) adjust the degree of hardening
to be 2.5x to 5x range. (But modern emulsions use blends of gelatin
and other polymers such as polyacrylamides.)
On Sun, 15 Jan 2006 13:39:34 -0800 (PST), "Rhody Simpatiko"
<aunt_rhody@oldgreygoose.com> said:
> Is there a easy way of determining whether or not gelatin has hardened?
> Apparently, hardening is not an all or nothing affair. It hardens over
> time, differently with different hardening agents and dilutions. And now
> I'm reading that the ph is also a factor which I suppose means support
> selection is also entered into the mix.
>
> So, short of actually making a gum print and having it fail, is there
> some
> kind of clue to look for that will indicate that gelatin has hardened
> sufficiently? A chemical test perhaps?
>
Received on Sun Jan 15 16:26:42 2006
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