Volume 14, Number 1, Jan. 1992, pp.28-29

Technical Exchange

Watermark Query

Land grants signed by the last Mexican governor of Alta California are currently in the conservation laboratory at the Pacific Sierra Region of the National Archives. The documents, dated 1846, were executed on thin, machine-made wove paper. Fiber analysis indicates the paper to have been manufactured from flax with the inclusion of shives. All but four of the nineteen pages bear a distinct watermark, shown below (actual size).

The watermark runs along the entire left edge of the sheet. The papers were transparentized in an attempt to imitate parchment. I have been able to find only one reference in the literature to a transparentized paper with a watermark, a brief mention of the same watermark illustrated here. It seems to be related to the type of watermarks used for security papers in the manufacture of currency, stamps and legal documents. I would like to find out more about this paper. If anyone has any helpful hints, leads, or information, please contact:

Jane Klinger
National Archives
1000 Commodore Drive
San Bruno, CA 94066 415/876-9018

Masking Tapes

We have been using two masking tapes recommended for surfaces where regular masking tape is too sticky. It is a good idea to test the tape before use, to prevent any damage. These tapes are available from paint supply companies. If they don't stock them, they can usually order them. Both tapes come in 60 yard rolls. 3M Scotch Brand Masking Tape

#2090 Long Mask (Blue), which is available in 1",1.5" and 2" widths. Approximate costs are $3-$5.

3M Scotch Brand Masking Tape #2070 Safe Release (White) is available in l" and 1.5" widths.

Approximate costs are $3 and $3.50.

Source for Japanese Papers

In addition to offering a range of traditional Japanese papers, Hiromi Paper International will work with conservators to commission custom papers for special applications. Their standard line includes both handmade and machine made papers and their sample/price sheet gives information about the furnish, cooking, bleaching, drying, and pH of the sheets. Prices are competitive. Hiromi Paper International

1317 Abbot Kinney Blvd.
Venice, CA 90291
213/396-7900 213-366-5738 (fax)

Dust Cloths

Conservation Materials, Ltd. offers a dust cloth called Dust Bunny, manufactured by Leap Frog Technologies, that works in a different manner from ordinary treated dust cloths. ACM blurb describes the cloth (which is their Catalog No. 2150-001): "a very good electrical insulator and thus holds an exceptionally high static electric charge generated during the wiping motion. It is this charge which attracts the dust particles. Attraction alone is not sufficient to make the Dust Bunny work. You must also retain the dust particle and prevent its redeposition onto the surface of the artifact. Dust Bunny cloths have a surface area of nearly 50,000 square feet per pound. Further, as the static charge is developed during wiping, each fiber repels neighbors and tries to stand alone, making a cloth surface full of channels and tunnels ideal for trapping tiny particles. Dust Bunny cloths are free of all chemicals, lint free, washable and reusable. Each cloth is 17" square and pure white in color." Conservation Materials Ltd.

Library of Congress Responds to Deacidification Bids from Industry

The Library of Congress has turned down offers from three industrial firms to undertake the massive task of deacidifying, and thus preserving, millions of books in its collections. "None of the offers received could meet all of the technical and business requirements," said Gerald Garvey,the Library's deacidification program manager. "We wanted industry to carry out this task, and so far, they haven't been able to do it. We are sorely disappointed."

Since the early 1970s, Library of Congress preservation specialists have been exploring techniques to preserve books printed on acid paper--that is, most books published since the mid-1800s. Thanks to the acid present in the paper, such books slowly disintegrate. As a part of a cooperative conservation program to preserve information in the most fragile books in the nation's libraries, the Library has been microfilming thousands of valuable books each year, a slow costly process, even as its specialists have tested chemical processes to remove the acid from books en masse.

In September 1990, the Library issued a "request for proposals" from industry for deacidifying its book collections. The performance requirements were set after year-long Library consultations with conservators and preservation scientists from around the world. The Library solicited comments from industry; six firms responded with information on their various processes. The General Accounting Office reviewed the "request for proposals" before it was issued.

The final request for proposals included requirements for toxicological and environmental safety, process efficacy and other preservation needs, the aesthetic appearance of treated books--as well as the firm's business plans and financial information.

In addition, potential contractors (or "offerors") were required to treat a set of 500 books to confirm technical information contained in their proposals and to show conformance with the Library's specifications. The Library, via competitive process, picked an independent testing laboratory, The Institute for Paper Science and Technology in Atlanta, Georgia, to test the treated demonstration sets of books.

Thus, the Library required that each would-be contractor demonstrate its ability to do the job. Although a half dozen firms had shown interest earlier, only three firms applied for a contract.

Data from the Institute's analyses were documented in a set of reports relating to extension of book life, alkaline reserve, appearance, odor, and other factors. (These data will be published, once permission is obtained from the offerors). In March of 1991 the 14-member Source Selection Evaluation Board, headed by Peter Johnson of Congress's Office of Technology Assessment, convened to evaluate the offerors' submissions. The Board evaluated written proposals submitted by the offerors, the data obtained from the independent testing laboratory, and first-hand information gained from site visits to the treatment facilities. Data collected from the 500-book demonstration sets was vital to the Board's conclusion that no offeror satisfied all the technical requirements of the solicitation. The Board submitted its findings to the Library in July 1991. Following extensive study of the Board report, the Library decided to cancel the procurement, and the offerors have been so notified.

"The enormous challenge of preserving a substantial portion of the Library's collections from loss through acidic embrittlement remains," said James H. Billington, the Librarian of Congress. "With the support of the Congress, the Library plans to continue efforts to identify and begin using viable, affordable, technically acceptable mass deacidification technologies for saving its collections.

The Featured Catalog

Founded by Steven Weintraub, formerly head of the Conservation Processes Group at the Getty Conservation Institute, Art Preservation Services offers a tantalizing line of environmental monitoring and control equipment as well as consultation services.

The brochure for their ARTEN line, which includes UV meters, hygrothermographs, silica gel, and sling psychrometers, veers off into unusual territory with a portable infrared thermometer that can be used for remote sensing in exhibits, photo sessions,etc. If that isn't enough to set your neurons atwitch, perhaps you can be tempted by an ultrasonic leak detector. Designed to find minute air leaks in display cases, the instrument consists of a small tone generator that is placed inside the case and a hand- held scanner.

Less grand, but no less appealing is a nylon/aluminum/ polyethylene laminate intended for use as a barrier material in display cases, shipping crates, for $6/yd.

To receive the brochure, write to:

Art Preservation Services
539 E. 81st Street
New York, NY 10028
212/988-3950 212/794-3045 (fax)

Erratum

In the last issue of the newsletter, the phone for Gilbert Garcia should have read: 818/281-9456.