Re: Printing gum on hard surface

Hi Katherine,

But when you said you exposed it long time, did you mean expose the gum that
is coated on glass for a long time? And since the glass is so "slick" the
gum didn't hold to anything as you said/saw.

My suggestion (and again, I don't know if that will work) was that you
prepare a thick gum layer on porous paper, expose it heavily, and wet it
briefly and squeezee it on a piece of glass (or mylar might be even better).
Keep it there for a few minutes or even an hour, then wet the back side of
the paper or soak it in water, and then peel it off; and then soak the glass
or mylar under water and wait for the unhardened part to dissolve while
leaving the hardened piece there. This has to be very carefully done,
otherwise the hardened part will be washed away too. Basically a carbon
transfer method.

But that is if you are interested in a piece of hardened gum. If not,
probably your test on mylar or non-glare glass is sufficient.

And typing this is making me so wanting to do some tests, but maybe I should
not....

Dave S

----- Original Message -----
From: "Katharine Thayer" <kthayer@pacifier.com>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Friday, September 03, 2004 7:37 AM
Subject: Re: Printing gum on hard surface

> Dave Soemarko wrote:
> >
> > > The chemist I'm working with thought it would
> > > be a simple matter to coat glass with dichromated gum, expose, wash
and
> > > dry it and then peel off a sheet of nice hardened gum. Don't I wish!
> >
> > Oh, sorry I didn't read this email before replying to the previous one.
If
> > you want a piece of dry hardened gum, maybe you could try coating it
> > thickly, expose, and do something similar the carbon transfer, except
that
> > this is a gum transfer. You can transfer it to a piece of pure glass, or
the
> > slick side of mylar.
> >
> > But I haven't done that myself. It's just a suggestion.
> >
>
> Well, I actually tried that in the interest of making more hardened gum
> faster, but I couldn't make it work. I don't think gum works the same
> as gelatin in this regard. And in fact, we all know that one reason for
> failure in gum is to get the coating too thick; it just flakes off. I
> put these thicker layers out in the sun and exposed them for a very long
> time, but no go.
> kt
>
Received on Sun Sep 5 08:28:48 2004