Digital BW, The Print

Robert,

Thanks for the good information. We talk a lot about acid-free papers 
but the issue is much more complex than that as you point out. Your 
earlier posts on OBA's is in Files section.

Martin Wesley

--- In DigitalBlackandWhiteThePrint@y..., "Robert Rex" 
<chameleon@i...> wrote:
> Excellent post, Martin!
> the only thing i would add is that the "amount" of buffering agents 
> tend to affect the archivalness of a paper.  Libary of Congress 
> standards indicate that they consider an archival paper to have not 
> more than 3-5% of fillers (fillers include buffering agents like 
> CaCO3, pigments like titanium dioxide or silica) by weight. (my 
> memory may be off here, but i think i posted the LoC website in an 
> earlier post and Martin bookmarked it in the Files section of this 
> list.
> Fillers are measured by the amount of ash resulting by burning the 
> paper. 
> Museo contains 2.8-3.3% filler or buffering agent (Calcium 
carbonate 
> in Museo's case; this is the most common alkaline buffering agent--
> arches, etc have used this for centuries.)  We have tested some 
> papers--internally--with an ash content as high as 10%.
> hope this helps,
> robert rex
> crane & co
> 


(snip)