What role does the Glyoxal play? Is it to harden, or maintain the semipermeable gel state?
The Glyoxal hastens drying. It also improves adhesion to glass. It is not 100% required. An unhardened coating is functional. Actualy, Formalin works better for this. But my sinuses and eyeballs started protesting about Formalin.

If you actually have a gel state... is it more like syrup than a gel?
The "gelatin substitute" is syrupy. It will not set-up. However, after adition of AgNO3 solution the look and "feel" of the emulsion is virtualy the same as a gelatin emulsion.

How long after prep. can you process the plates? (is there a known window, or does the surface remain permeable to water forever... will it dissolve away without the glyoxal?)
While I have not done a formal, deliberate study. The emulsion still "works" after days of sitting at room temperature. I have exposed and developed plates 3 days after coating.

I think I am familiar with the observation you made about sensitization of such emulsions...
it has been observed before.
Thanks for the validization.
Unfortunately, I know more about gelatin than any good vegetarian ought to....
I should be ashamed!
I am ashamed (of myself). But I will not be mixing the "gelatin substitute"
with sugar,coloring and flavoring to be consumed by me or anyone else.

You mentioned you hope "they" will manufacture it... is that part of the process difficult or time consuming?
The making of the "gelatin substitute" Is time consuming and labor intensive. But it is not "rocket science".
I don`t think many people would want to make it at home. ----------------------------------------------------------------

Looking forward to those pictures you promised![/QUOTE]
I had other mundane stuff to do. Hopefuly will coat tonight.