Re: PVA vs. PVA

What I am basically working is to produce very large paper prints of 1.00
mts x .80 mts using alternative processes.
Yesterday I prepared a hand made paper of that dimension and "drunk" 150 cc
of PVA acetate sizing at 1:5 ratio (it also gained weight).
This was a single sheet of paper.
So far my tests with 60 cms x 40 cms prints are fine (I am using Cyano and
Van Dyke so far but I will move afterwards to gum bichromate).
I found that PVA acetate sizing for these dimensions and eventually number
of prints is easier than gelatin+hardener sizing but I will only know at the
end.
I hope this explanation complies with your WHY question.
Giovanni
pd No problems producing a large negative and getting the proper UV source.

----- Original Message -----
From: "Judy Seigel" <jseigel@panix.com>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Monday, August 01, 2005 11:30 PM
Subject: Re: PVA vs. PVA

>
> On Mon, 1 Aug 2005, Giovanni Di Mase wrote:
> >
> > Any idea what the stock ratio (dilution, pigment and bichromate) and
would
> > be using glue (any Elmers or Gloy) instead as arabic gum to start with?
>
> I'd start with normal gum ratio, which goes anywhere from equal to 1 to 2
> to 2 to 1 or more I suppose.
>
> > I am assuming that Gloy is manufactured out of PVA acetate as all other
> > glues and as I read from Katharine it is not water solubable therefore
could
> > not replace the arabic gum, but I have also read the opposite
>
> If it isn't water soluble when it's dry, obviously you can't make a gum
> print with it, because it won't differentially dissolve. On the other
> hand, whatever you're using for a size, has got to be NON-water soluble,
> or it will wash off even as you coat the emulsion.
>
> > I am going to try anyway and compare to the PVA alcohol glue, I just
need to
> > have some clear ideas from where I am going to what I can find.
>
> Well, I think one more thing, though I hope you won't think I'm being
> snide... That is, WHY ? I mean, what benefit do you expect from what are
> after all marginal, or anyway minority materials? Which is not to say
> there are none (as I recall Joe Smigiel uses rabbitskin glue) but I have
> yet to get an idea from this discussion of what they're supposed to be. (I
> remember, BTW, in fact I have samples in the file, how hard Mike Ware
> worked to get decent gradation with PVA. Not to say he didn't ultimately
> get it -- I have no idea -- but that gradation is almost unavoidable with
> a properly coated, exposed, and developed *gum* print.)
>
> That goes not just for you of course, but for the whole discussion.
> What is it about?
>
> Judy
>
Received on Fri Aug 5 12:19:52 2005