Re: Water and gum coating (was: tanning theory)

>
> >
> > "Grimm et al also showed one more step from there. If the dichromated
> > PVA does not contain certain amount of moisture, this PVA-Cr(III)
> > complex undergoes further photosensitive reaction, which loses water
> > and chromium drops out of the PVA complex and renders the PVA soluble
> > again. This, they say agrees with the experience from phosphor coating of
> > color CRT's, but also seems to agree with some of the careful gum printers
> > in this list talking about moisture level in the coated layer during
> > exposure."
> >

I was so annoyed by the overreaching attempt to connect this research to
gum printing that I forgot to ask for a reference. Do these researchers
actually demonstrate, or do they merely assume, a PVA-Cr(III) complex?
If they actually demonstrate it, then I very much want to see that.
Katharine Thayer
Received on Mon May 17 15:55:20 2004