Documents should be stored in low-lignin, buffered file folders, with a maximum of about 15 sheets per folder. The folders should then be placed in archival-quality document storage boxes as close to the size of the folders as possible. All folders in each box should be the same size. Boxes should be full enough to prevent slumping of the contents; partially full boxes can be filled with spacer boards available from conservation suppliers. Do not stuff boxes. This can cause damage when sheets are removed and refiled. See Preservation-Quality Enclosures for general information on enclosures.
An alternative to boxed storage is a standard baked enamel file cabinet equipped with hanging racks and hanging folders. Archival-quality hanging folders are available, but the conventional kind are acceptable as long as the enclosures within them are buffered.
Store objects of the same size and category together whenever possible. Archivists habitually organize collections by subject group, but objects of differing bulk and weight can cause damage from uneven pressures in a drawer or box. It is not advisable to store single sheets in the same box with books or pamphlets unless there are separate enclosures and supports for each category of material. Generally speaking, heavy objects should be stored separately from lighter objects, as should bulky objects.
Parchment and vellum are highly susceptible to damage from fluctuations in relative humidity and thus require stringent humidity controls. Such documents should be enclosed for additional protection. Suitable enclosures include encapsulation, folders, matting and framing, boxing, or a combination of these techniques.
Ephemera may have raised surfaces or three-dimensional decoration. Items should be grouped by size and type (e.g., postcards, printed material, documents), enclosed to protect them from chemical migration and mechanical damage, and stored to support the structure of the artifact (encapsulated, boxed, stored flat or in hanging files). Some vendors of archival supplies offer custom-size storage boxes and sleeves for common ephemera such as postcards and stereo views, or they can produce custom-size boxes in large quantities to meet special needs.