Re: Glyoxal?

On Jan 11, 2006, at 10:34 PM, Yves Gauvreau wrote:

>
>
> While I'm at it, I read it's yellow in color, does this color stays
> in the
> gelatine when sizing?

This is one of those questions you'll get different answers to. If
you want to read a whole lot about it, look for "glyoxal yellowing"
in the archives.

I don't see the yellow in the solution; the hardened gelatin I mix
looks pretty clear and colorless. Many gum printers have noticed
that glyoxal-sized papers may turn an ivory color after sizing (this
ivory color is what people mean when people talk about glyoxal-sized
papers turning "yellow.") Judy found that the color change can be
averted by rinsing after sizing. The Arches bright white paper I
use does darken to a very ivory color, but I don't bother to rinse
as a step in the sizing process because the development bath in the
gum process restores the paper to the original pristine white. So I
don't see any necessity for a separate rinse. But you'll need to see
if that works with your paper, or not.
Katharine
Received on Thu Jan 12 09:33:49 2006