Digital BW, The Print

David, Mark, Martin:
this is for public posting.
one of our project chemists found this web site that will be good for 
posting on the list, and probably adding it to the Files section.
this is the Library of Congress and their specifications for archival 
papers.  I would suggest clicking on the first option in the card 
stock category.


http://lcweb.loc.gov/preserv/supply/specific.html.  

Brief Summary of the specifications:  The stock must be free of 
optical brightening agents, the pH, cold extract, range 8.0-9.5, and 
calcium carbonate should be between 2 and 5% for Buffered papers and 
a pH of 7 and no CaCO3 for unbuffered papers.

these are some of the questions you all should be asking of the 
various paper mfgs/distributors.

thanks for your attention
robert rex

--------------------------------------------------
Antonis has placed the above link in the "Bookmarks" section of the 
group's homepage under the "Reviews and Info On-line" folder for 
future reference.

Okay, Robert, what is the cold extraction pH of Museo? ;-)

Also, as an aside, while the information you will find at this link 
clearly spells out what is needed for optimum paper permanence, we 
still don't know how these properties effect the image permanence 
using different inks or media.

Martin Wesley

At 02:40 AM 9/6/01 -0000, you wrote:
{snip}

> Okay, Robert, what is the cold extraction pH of Museo? ;-)
> 
> Also, as an aside, while the information you will find at this link 
> clearly spells out what is needed for optimum paper permanence, we 
> still don't know how these properties effect the image permanence 
> using different inks or media.
> 
> Martin Wesley

I do have these specs for both cold and hot pH extracts.  but i am
travelling and don't have the specs with me.  I will ask one of our project
chemists to email me the specs and will post here forthwith.
sorry for the delay, and thanks for posting this on my behalf, martin.
sincerely
robert rex
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chameleon@...


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Robert,

Welcome back. Sounds like you escaped from the company intranet by 
taking a trip!

Thanks for all the information in the e-mails, this post and the 
three that follow.

There is one item regarding OBA's which concerns me and that is the 
question of whether they simply stop fluorescing or if they break 
down to produce chemicals that effect paper permanence.

Martin


--- In DigitalBlackandWhiteThePrint@y..., Robert Rex <chameleon@i...> 
wrote:
> At 02:40 AM 9/6/01 -0000, you wrote:
> {snip}
> 
> > Okay, Robert, what is the cold extraction pH of Museo? ;-)
> > 
> > Also, as an aside, while the information you will find at this 
link 
> > clearly spells out what is needed for optimum paper permanence, 
we 
> > still don't know how these properties effect the image permanence 
> > using different inks or media.
> > 
> > Martin Wesley
> 
> I do have these specs for both cold and hot pH extracts.  but i am
> travelling and don't have the specs with me.  I will ask one of our 
project
> chemists to email me the specs and will post here forthwith.
> sorry for the delay, and thanks for posting this on my behalf, 
martin.

> sincerely
> robert rex
> PLEASE NOTE:  WHEN REPLYING, ENSURE THAT EMAIL ADDRESS READS--
> 
> chameleon@i...
> 
> 
> IF THE "pop" IS PRESENT IN THE EMAIL ADDRESS, 
> DELETE THE "pop."  
> THIS IS IMPORTANT, 
> OTHERWISE I WILL NOT RECEIVE YOUR MESSAGE.

At 11:03 PM 9/6/01 -0000, you wrote:
>  Robert,
> Welcome back. Sounds like you escaped from the company intranet by 
> taking a trip!
> 
> Thanks for all the information in the e-mails, this post and the 
> three that follow.
> 
> There is one item regarding OBA's which concerns me and that is the 
> question of whether they simply stop fluorescing or if they break 
> down to produce chemicals that effect paper permanence.
> Martin
><> 
>> At 02:40 AM 9/6/01 -0000, you wrote:
>> {snip}
>> 
>>> Okay, Robert, what is the cold extraction pH of Museo? ;-)
>>> Also, as an aside, while the information you will find at this 
> link 
>>> clearly spells out what is needed for optimum paper permanence, 
> we 
>>> still don't know how these properties effect the image permanence 
>>> using different inks or media.
>>> 
>>> Martin Wesley

Martin, all:
The spec is 7.5 to 9.0 for an uncoated sheet.

Museo               cold extract:  8.2
                    hot extract:   8.3

Regarding, OBA's in the paper, it is my understanding that the UV rays end
up breaking down the OBA's so that they stop flourescing. i don't know
whether chemicals are produced in that process which would affect paper
permanence.  will ask and report back.
thanks
robert rex
PLEASE NOTE:  WHEN REPLYING, ENSURE THAT EMAIL ADDRESS READS--

chameleon@...


IF THE "pop" IS PRESENT IN THE EMAIL ADDRESS, 
DELETE THE "pop."  
THIS IS IMPORTANT, 
OTHERWISE I WILL NOT RECEIVE YOUR MESSAGE.

--- In DigitalBlackandWhiteThePrint@y..., Robert Rex <chameleon@i...> 
wrote:
(snip)

Robert,

Once again we appreciate you coming through with the hard numbers. 
Museo certainly fulfills all the requirements of a paper that will 
literally last for centuries. 

I really appreciate your efforts to educate us in the area of OBA's 
and I hope that you will be able to pick the brains of your R&D 
wizards to let us know what happens to these chemicals once they stop 
doing their job. To avoid any confusion Museo and other Crane papers 
contain no OBA's.

Thank you,

Martin Wesley


> 
> Martin, all:
> The spec is 7.5 to 9.0 for an uncoated sheet.
> 
> Museo               cold extract:  8.2
>                     hot extract:   8.3
> 
> Regarding, OBA's in the paper, it is my understanding that the UV 
rays end
> up breaking down the OBA's so that they stop flourescing. i don't 
know
> whether chemicals are produced in that process which would affect 
paper

> permanence.  will ask and report back.
> thanks
> robert rex
> PLEASE NOTE:  WHEN REPLYING, ENSURE THAT EMAIL ADDRESS READS--
> 
> chameleon@i...
> 
> 
> IF THE "pop" IS PRESENT IN THE EMAIL ADDRESS, 
> DELETE THE "pop."  
> THIS IS IMPORTANT, 
> OTHERWISE I WILL NOT RECEIVE YOUR MESSAGE.