What We Do
Dianna Samuelson restoring scrapbook.
The staff of the Conservation lab uses many hands-on techniques on a daily basis, working with archival materials created over several centuries. The staff uses processes such as disbinding, paste washing, washing and flattening, leafcasting, pH testing, deacidification, sewing, tape removal, mending, rebinding, leatherwork, hand sewing of headbands, encapsulating, laminating, matting, gold stamping and box-making.
To illuminate some of the processes further, there follow some short descriptions.
- High acid content makes paper turn brown and brittle. To determine the level of acidity in a document, the staff uses two methods of testing the pH. One is with an "archivist's pen" with which a dot is put on the paper that turns yellow if the paper is acidic. The other involves pH test strips which give a more exact level of acidity. If the item is valuable enough to warrant the expense of deacidifying, the staff sprays it with Wei T'o Deacidification Solution to neutralize the acid and leave a magnesium buffer to protect against future acid attack. This is done in the lab's spray booth, which evacuates the fumes.
- Encapsulating is a form of protecting a document by sandwiching it between two clear polyester layers that are heat sealed at the edges. The item is free inside and can easily be retrieved if needed. This is a very reversible method, which usually makes it the first choice. Laminating is a heat process done with special archival tissue. It is less reversible but is sometimes the most appropriate choice.
- Many people are not aware that it is possible to wash paper. Conservators wash paper to remove acidic components, old sizing, stains, and/or to relax creases. They test inks to be sure they are fast, before immersing a document in filtered water.
- Paste washing is a method of removing the old spine-lining fabric and glue, using polyvinyl acetate adhesive and wheat paste. The pastes are applied to the spine after the book is disbound. They soften the old materials, which are then scraped off.
- Leafcasting is a technique for filling in voids in paper. It entails securing a damaged page on a support frame under water and pouring over it a slurry of filtered water and paper pulp. The slurry fills the void and recreates paper. Another form of filling voids is to use a piece of appropriate paper, shaped to fit, with slightly overlapping edges, pasted into place.
- Sewing is often done by hand over flax cords or cotton tapes on a sewing frame, as it has been done for hundreds of years. It may also be done in sections on either the Singer or Oversewing machine.
Deacidifying a Native American land deed.
Encapsulating a Huron River survey map.
Cartes de visite soaking in a tank of filtered water.
Pastewashing the spine of a book.
Ledger volume restored with leafcasting.
Ann Ringia sewing a book.
Before and after conservation of a badly damaged blueprint