Re: PVA for gum printing

> What conflicting
> statements have you heard about ESTAR?

One source classifies ESTAR as polyethylene terephthalate (PET) and the
other one, probably more likely so, points out it was formed of unsaturated
polyester (UP). The latter would be significantly different from PET.
According to my Plastics Encyclopedia Estar is a trademark of Mitsui Toatsu
Chemicals Inc., Tokyo.

Martin

----- Original Message -----
From: "Robert Schaller" <Robert@RobertSchaller.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Wednesday, September 08, 2004 12:24 AM
Subject: Re: PVA for gum printing

> Thanks, Martin -- I will give your TAC method a try. What conflicting
> statements have you heard about ESTAR?
>
> Robert Schaller
>
> On 9/7/04 1:39 AM, "MARTINM" <martinm@SoftHome.net> wrote:
>
> > Having read some conflicting statements about its composition, I am not
sure
> > about Estar. If Estar was similar to PET (polyethylene terephthalate),
> > that's to say Mylar, Cronar etc. it would require a great deal of effort
to
> > coat gelatin or gum on it like: flame/plasma/corona treatment, etching
etc.
> >
> > TAC (triacetate) film is a lot easier to handle: 2 min in a 10% alkali
> > hydroxide + (deonized) water rinse will do the job.
> >
> > Martin
> >
> >
> > ----- Original Message -----
> > From: "Robert Schaller" <Robert@RobertSchaller.net>
> > To: <alt-photo-process-l@sask.usask.ca>
> > Sent: Monday, September 06, 2004 7:35 PM
> > Subject: Re: PVA for gum printing
> >
> >
> >> Dear Katherine,
> >>
> >> I indeed can't see why mylar would introduce any impurities,
certainly
> >> not water-soluble ones, and wouldn't these be the problem? I also want
to
> >> applaud your efforts in this, as it seems long overdue that someone
> > conduct
> >> this investigation in an orderly, scientific fashion. I wish I was set
up
> >> to do it. I am curious about how the investigation will proceed. What
> >> tests exactly is the chemist planning to do? I get the impression that
> > just
> >> hardened gum (or PVA) will be tested first; what next? As I said, I am
> > very
> >> curious.
> >> Also, on the point of gum on hard surfaces. What about ( and this
is
> >> probably my question more than yours) getting gum to stick to
polyacetate
> > or
> >> polyester (Kodak's 'Estar') film base? The issue seems related, in
that
> > it
> >> is really asking, how do you get gum to stick to a non-water adhering
> >> surface, be it rigid or flexible? I have cheated and used Kodak's
already
> >> adhered gelatin layer as a subbing layer,as it is already there and is
> >> optically transparent, but this avoids the question. Obviously, Kodak
et
> >> al. know how to get gelatin to adhere -- what's their trick, and would
it
> >> work as well for gum? Does anyone have any methods, ideas, or
> > suggestions?
> >>
> >> Robert Schaller
> >>
> >>
> >>
> >> On 9/4/04 3:32 AM, "Katharine Thayer" <kthayer@pacifier.com> wrote:
> >>
> >>> Katharine Thayer wrote:
> >>>>
> >>>
> >>>> Do you or anyone know of any reason why mylar shouldn't be used for a
> >>>> substrate for hardening the gum?
> >>>
> >>> No one has answered this question; I take the silence to mean that no
> >>> one knows any specific reason to distrust mylar as a substrate. At any
> >>> rate, I will wait for the go-ahead from the chemist to be sure, before
> >>> finishing the project on mylar. Thanks for suggestions,
> >>> Katharine Thayer
> >>
>
Received on Wed Sep 8 00:59:50 2004