Portland History: document conservation

A major component in the work of bringing history out to our patrons is the conservation of archival materials. “Archival” can be of any vintage- old or new- providing the content demonstrates a documentation of the life and activity of a subject, and for us it is Portland history.

The pictures below describe how a print from a volume of the Portland Harbor Commissioners’ reports from 1855 has recently been restored and encapsulated here in the Portland Room of the Library. Considering the time and accuracy of this print, knowing both the dates of the Civil War and especially the year of the Great Fire (1866), this landscape provides remarkable detail about the city.

The print, as we found it folded into the book’s flyleaf, had been damaged over the years- and being on thin and acidic paper it required extensive repair. This intricate landscape is now restored, encapsulated, and can be viewed !

The first stages for conserving this document included cleaning, flattening (with weights and light ironing), and consolidation (repairing the numerous torn surfaces and breaks in the paper).

Here is a closer view of one of the breaks in the paper, along with some information about the publisher- at 53 Exchange Street. The street we associate today with the Old Port District had been Portland’s “printers’ row,” filled with publishers, bookbinders, stationers, paper companies, and newspaper offices.

Using paperweights, the creases and tears are repaired on the verso (back) side of the document, thus concealing the latticework of handmade acid-free paper tissue needed to reinforce the print.

For repairs such as these, we use Kozo tissue and a mixture of PVA and methylcellulose adhesives. The archival requirements for permanence (nonacidic materials) and strength (long-fibered alkaline papers) are met.

With careful restoring, the torn edges can be brought back together as closely as possible by matching the tear with the repair. It is also an opportunity to really study the artifact. Notice the fine city of Portland seal in the image at right.

After all the repairs were fully dry, the print was placed under weight overnight. In this image, the print rests on a sheet of Permalife 80lb paper cut to the exact size of the print. The alkaline substrate will act as a buffer to raise the pH of the print itself- as well as provide some strength during future handling of the item within its mylar enclosure.

At last, the print is encapsulated between two sheets of archival mylar, while supported by the Permalife paper base. The mylar sheets are attached along the outer margins, beyond the perimeter of the print, so that no adhesive is touching the document. As well, each of the corners has a cut air vent so that the print can “breathe.”

Come visit historic gems such as the 1855 Portland landscape, here in the Portland Room. We repair approximately 100 books, maps, and documents per year. We’re also happy to answer your preservation and conservation questions.

posted: , by Abraham
tags: Library Collections | Adults | Seniors | Portland History
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