Mat - matting

Material used to protect and present works of art on paper. Constructed from sheets of stiff paperboard, mats usually are hinged and joined together with tape so that the bottom part, usually quite thin and smooth, supports the work; and the other, often textured and colored, provides the window or opening for viewing. Poor quality wood-pulp mat board made from bleached, unrefined wood pulp, is the most common matting, but should be avoided because it darkens and becomes brittle. Persons wishing quality Matting should request conservation-quality mat board that has a neutral or alkaline pH of 7 or above when manufactured. There are three kinds: rag board made from cotton rags, buffered rag board that has calcium or magnesium carbonate to neutralize acidity, and conservation board made from chemically purified wood pulp. Source: Arthur W. Schultz, "Caring for Your Collections", Harry N. Abrams, Publishers, p. 42-43. (LPD)