[alt-photo] Re: Paper Negatives

[Diana Bloomfield]

Here's the blurb that Gamblin puts on their site.   Of course, they  
are making and selling it.  But I think it was Jim who first told me  
about using it (thanks, Jim!), and around the same time, I went up to  
my local art store, looking for some paper-- and the owner, who always  
seems quite knowledgeable about all things art-related-- asked me what  
I was working on, so I told him, and then I started complaining about  
gelatin sizing, glyoxal, etc.  He immediately asked why I wasn't using  
something like PVA-- so we had this long conversation about it, and he  
said painters buy it all the time up there-- He seemed confident,  
conservation-wise, that it wasn't an issue.  Of course, like Gamblin--  
he's also selling it.  But given what else I consistently buy up  
there, I doubt he stands to make much money off pushing PVA on me, or  
on other unsuspecting customers.

  PVA (poly vinyl acetate) is a synthetic-- I think.  (To answer  
someone else's question-- no hardener needed.)  Using it improved my  
life (and gum prints) greatly.  :)


POLY VINYL ACETATE (PVA) SIZE
Diluted with distilled water, PVA size is a contemporary size for  
fabric support. Conservation scientists recommend painters use neutral  
pH PVA size on linen and canvas instead of rabbit skin glue. PVA  
provides a good size layer that seals the fabric but does not re- 
absorb atmospheric moisture, swell and shrink like rabbit skin glue  
does. There are hundreds of different formulae of PVA. We acknowledge  
and appreciate the research of the Canadian Conservation Institute  
that helps painters and conservators identify the best PVA to use.  
Gamblin PVA Size is made from PVA that has a neutral pH and does not  
yellow. It also retains its flexibility and does not emit harmful  
volatiles.

On Feb 22, 2010, at 4:50 AM, Michel Debar wrote:

> PVA wood glue used for sizing, is it safe ?
>
> I would certainly worry about the conservation of prints sized with  
> PVA, as
> its long term effect on paper has not, to my knowledge, been studied  
> very
> seriously. As a minimum, I would stay away from "wood" glue, branded  
> or not.
> Its composition has little chance of being  known, and of being  
> stable over
> time. The acidity of these glues may vary, and not be suitable for  
> some
> processes. They may take as little as five years to become brittle -
> however, this may not be not too much of a concern given the very  
> thin layer
> used.
>