Volume 26, Number 2
Aug 2002

Cotton Paper and pH at Southworth Paper Co.

Bill Minter became concerned about the pH of Southworth paper when he noticed that their Parchment Deed was in a box that was not labeled "Acid-Free." He then wrote to the company for an explanation. Their exchange of letters follows:

To: Southworth Paper Co.
My business is the preservation and conservation of books and documents. I recently consulted with a client in Illinois who uses your "PARCHMENT DEED" paper for their most important legal documents. We were discussing the treatment we are doing on their oldest documents which includes deacidification. When we discussed their current documents, they told me about your paper. Upon examining the box, I saw nothing about "Acid-Free". I know that 100% cotton is the best paper, but it should also be at least neutral pH. When we tested your paper with the Merck ColorpHast strips, we obtained a reading of 5.3. That is extremely low and is not acceptable for long term. I wonder what you have to say about my findings? If indeed your paper is a low pH, I wonder why you would continue, in light of information that is available.
William Minter
Bookbinding & Conservation, Inc.
WMNTR@aol.com

Dear Mr. Minter:
We acknowledge receipt of and thank you for your inquiry concerning acid-free paper.
In response to your inquiry, all Southworth and Eaton papers measure approximately 5.5, with zero being acid, and 14 being alkaline or acid-free.
Southworth and Eaton do, however, offer items which are specifically acid-free—Southworth item 603C 25% cotton white (20lb) recycled paper and Eaton items 35-120-10 100% cotton bright white (20lb) and 35-940-10 25% cotton bright white (20lb) Thesis papers. (If you wish additional information on any of these items, please feel free to let me know.)
Please keep in mind, though, that although acid is detrimental to permanence, cotton content is also a consideration for special documents, in that cotton lends itself to durability. A rule of thumb states that for each percentage point of cotton fiber, a user may expect one year of resisting deterioration by use (the handling to which paper may be subjected).
Acid-free mills use calcium carbonate in place of fiber. This process leads to limper products which detract from their quality feel. Since most consumers use feel to distinguish quality paper, Southworth does not want to alter the unique feel of their papers.
We trust that we have met your particular need for information in this respect. However, we ask that you please feel free to contact us again as required.
In the meantime, we again thank you for your inquiry and for your on-going support of Southworth fine business products.
Christine Howard
Consumer Relations Representative
Southworth Company
choward@southworth.com