WATER-STAINED CELLULOSICS: A LITERATURE REVIEW
MOST TEXTILE AND PAPER CONSERVATORS have been confronted with cellulosic artifacts bearing waterstains. The marks are characterized by a brown boundary that varies in intensity, width, brittleness, and permanence. The color of the line ranges from a light, barely perceptible tan to coffee-colored brown. On an undyed fabric the wetted and dried area will usually differ in color from the unwetted area, and as it is often lighter than the brown boundary itself, the brown line is ascribed to dirt and degradation products that are carried and deposited by the spreading liquid. The success of efforts to remove this staining with water or with water and surfactant is apparently related to the age and intensity of the mark, as well as to the initial processing of the substrate. Occasionally the browned margin is severely embrittled, breaking apart if flexed.
Since the fabrics or papers in question are usually old and often soiled, it is reasonable to suppose that the brown lines on such materials are a consequence of the soil and cellulose decomposition products moving with the water by capillary action. After immersing the objects in water, some conservators endeavor to prevent the browning at the edges or thicker, slower-to-dry portions by accelerating drying or by covering the object or its edges with cotton sheeting, net, or paper.3 Browning then occurs on the surface or edges of these secondary materials, which can be removed after drying. If damp cellulosic fabrics such as wet sheets are not dried promptly, a similar browning occurs on the surfaces in contact with the air. However, the occurrence of brown lines on clean cellulosic materials raises the question of how this effect can be due solely to soils. Consideration of the behavior of clean materials suggests that stains observed by conservators may have multiple causes.