Re: Mylar as base for carbon tissue

s carl king (sanking@hubcap.clemson.edu)
Mon, 22 Apr 1996 18:27:46 -0400 (EDT)

Philip Jackson wrote:

> I've experienced this problem - it's caused by something to do with the
> surface tension differences between the two materials. They bond all right
> when they're wet, but as the gelatine contracts when it dries it pulls away
> from the polyester base. I'd suggest (1) adding more plasticizer to your
> carbon tissue mixture - say up to 5% glycerine (or use the plasticizer in
> Mike Shorter's formula posted by Pete Frederick); (2) lay down a substratum
> on the mylar - say plain gelatine plus plasticizer with a chrome alum
> hardener; or (3) use mylar already coated with gelatine - either unexposed
> film that's been fixed or washed (Kodak 4125 worked for me but Aristo Litho
> didn't) or better yet, Kodak roller transport film - it's polyester already
> coated with soft gelatine and is used for cleaning automatic processors. A
> box of this isn't cheap, but you can probably find somebody who'll give you
> a few sheets to try.
>
> Philip Jackson
> pjackson@nla.gov.au
>
Philip,

I now remember (or so was reminded by Sam Wang, who gave me the stuff
back then) that the polyester I used a couple years back which worked
fine for me was what you refer to above, a material used for cleaning
the automatic processors in a local film/print processing operation.

Using this seems a much easier solution to placing a special coating
on Mylar D, which according to Luis has no coating.

Thanks for note. I am going to get some more of that material and
give it a try.

Sandy King
Sanking@hubcap.clemson.edu