Putting It Into Practice

Evaluating Your Collections

Oversized and Framed Materials

This map is brittle and suffers from waterdamage and cracking of its deteriorated coating.

Most cultural collections include at least a few maps, plans, and architectural drawings. Perhaps they are maps of the surrounding area or plans of buildings within the institution. Many cultural institutions also hold collections of artwork on paper, which may include posters, watercolors, pastels, and drawings of various kinds.

In general, these materials are subject to the same types of deterioration as paper documents. Many of these materials are oversized and may have been stored rolled for many years, complicating the problems of acidic deterioration. If materials that have been rolled seem too brittle to unroll for examination without causing damage, do not unroll them;consult a conservator for assistance. You may also encounter maps or other items that have been coated with varnish or other coatings, which has darkened and deteriorated.

The horizontal stains on this artwork are the result of wooden slats used in backing the artwork.

As noted elsewhere in this session, various copying processes used for maps and architectural materials have different vulnerabilities, and different processes stored in proximity to each other may damage each other, resulting in discoloration or fading.

Artworks on paper also exhibit a range of deterioration problems, which include fading or alteration of watercolor pigments (such as yellows or blues); smearing of pastel, charcoal, or pencil drawings; yellowing, fading, or browning of the paper support due to acidic deterioration; foxing; surface mold growth; cockling due to climate fluctuations; and tide lines or stains due to water damage.

Framed materials (which might include artworks on paper, documents, or photographs) often show characteristic signs of deterioration: browning and yellowing due to acid migration from poor quality backing materials (these might be wood, corrugated board, newsprint, or cardboard); knot patterns or a dark central stripe down the paper due to wooden slats used in backing; mat burn (darkened lines around the margin where the beveled edge of acidic matboard meets the paper); tape stains due to poor quality tape used for repairs; and adhesive stains due to poor quality adhesives used to hinge or mount the item to the backboard.