Conservation Lab

Cleaning treatments in the Conservation Lab range from basic stabilization to comprehensive procedures.

Once evaluated, we remove soil from an original by dusting it with eraser crumb and gently rolling the crumb across the surface of the paper artifact.

Extensive treatments may be required including washing, tape removal, stain reduction or lining for support. We test the media for solubility in water or solvents required to reduce acids and stains.

Acidic paper is supported on a polyester web and washed in a bath of deionized water amended with calcium carbonate to impart a buffer.

Washed drawings are blotted and air dried. Moveable tables in the lab help ensure the wet paper is transported as little as possible.

Repairs are often required to mend torn areas and stabilize the paper support. Working within the principle of “do no harm,” our methods of treatment are reversible.

In one bound manuscript copybook, the conservator used a light sheet to illuminate losses from below. The outline of the loss was transcribed onto tissue to perform the mending process.

Mending tears or a loss in the paper is accomplished by applying precipitated wheat starch paste to long-fibered Japanese tissue. A pasted strip of mending tissue is applied to the tear. Blotters and weights are placed on the new mend to help prevent cockling of the original.

Aside from treatments to collection items, artifacts are stabilized physically through a variety of techniques. We choose safe acid-free and neutral pH papers and boxes where appropriate. Archival storage for undersized manuscript diaries includes wrapping and filling the void of the folder with ethafoam stitched into place.

Panoramic photographs more than 5 feet in length receive a full Tyvek interleaf and are rolled onto acid-free tubes. Drop tags identify the item for library staff.

Panoramic photographs less than 5 feet are stored in sleeves made from Tyvek stitched to Melinex and placed in folders. The folders are placed in Tyvek slings for lateral drawer storage.

Controlling pests in the collections environment depends upon procedures which prevent them from entering the building coupled with knowledge to safely eliminate infestation at the source. A properly maintained environment will prove inhospitable to most insects, molds and mildews. Good housekeeping and frequent monitoring of collections also helps prevent pest infestation.

As part of our pest management program, we use a 1,500-square-foot area close to the loading dock to segregate incoming collections. It was designed to sequester materials brought from attics, basements, barns and other outbuildings.

Collections with evidence of previous infestation are subjected to a 48-hour freeze/thaw/freeze cycle at 20 degrees below Fahrenheit. We use two commercial Puffer Hubbard sub-zero freezers to freeze collections suspected of possible infestation. Cycling the temperature kills the insect at all stages – egg, pupae and adult.

Originals with mold or mildew are further segregated into a room that can be washed down after vacuuming with HEPA vacuums. We surface clean originals with heavy layers of soil in the segregated area. Conservation staff maintains a policy to cover hair, shoes, clothes and mouths whenever mold is present. Efficient HEPA vacuums are used to gently vacuum away mold. This tiled area is easily washed down for the next collection that may have a problem with mold.

These websites offer helpful information about the structure of paper, photographs and media.

• www.graphicsatlas.org
• www.webexhibits.org/pigments/intro/pigments.html
• www.nps.gov/museum/publications/conserveogram/cons_toc.html
• www.loc.gov/preservation/care/paper.html
• ipst.gatech.edu/amp/education/museum_virtual_tour.htm