Putting It Into Practice

Case Design

Case Design

Exhibit cases should be built of stable, pollutant-free materials and coatings. As with storage furniture, wood and wood composites are often used for exhibit cases, but they can be very damaging to collections because they emit volatile gases. Appendices B-1 and B-2 in ANSI/NISO Z39.79-2001 Environmental Conditions for Exhibiting Library and Archival Materials (PDF) provide detailed lists of materials considered safe and unsafe to use in the construction of exhibit cases.

If your institution has poor-quality cases and they cannot be replaced, any wood should be properly sealed, and the interior of the cases should be lined to prevent off-gassing. Wood should be sealed with a moisture-borne polyurethane or two-part epoxy sealant. Acceptable barrier materials include polyester film, 4-ply 100% ragboard, polyethylene foam sheeting, and Marvelseal (an adhesive-free laminate that is flexible and impermeable to gases and moisture). MicroChamber boards that contain activated carbon may also be an option. Barrier materials should be attached to the sides and the floor of cases; 3M double-sided tape no. 415 is recommended.

Other items that must be chosen carefully include fabric lining for cases, adhesives, and the gaskets used to seal the cases. Fabrics should have no additives and should be washed before use. Undyed cotton, linen, polyester, or cotton-polyester blends can be used. Silk is acidic, and wood off-gases sulphur compounds.