Re: Eliminating CaCO3 in buffer in "achival" watercolor papers

[etienne garbaux <photographeur@nerdshack.com>]

Loris wrote:

> You're right, my (maybe wrong) point was that: since acetic acid is a
> milder acid compared to HCl, it would do less harm to the paper,
> acutely... As far as I can read, acetic acid is the main cause of paper
> deterioration, so it has to be thoroughly washed out of paper when done.
Acids in general tend to deteriorate paper.  However, as a practical 
matter, I can say that I have used the aforementioned HCl treatment 
for the better part of 40 years on scores of different papers, and 
have almost never had a problem (of course, none of my prints is over 
200 years old yet, so I cannot say definitively that there will not 
be adverse effects that show up over a term of centuries, but none of 
the readily observable characteristics of the papers has been 
affected over a term of decades).  Note that I am scrupulous 
regarding washing, and have tested my washing procedures thoroughly.

The "almost" refers to one or two papers where the sizing reacted 
poorly to the HCl bath.  This was apparent immediately -- not a 
latent damage issue.

Best regards,

etienne