Maintaining the fiber piece will depend upon controlling the effects of Ultraviolet (UV) radiation from natural daylight and fluorescent light bulbs. One of the greatest threats to textiles is light. The amount of light (intensity) and the duration of exposure will determine the rapidity with which color changes in the tapestry will occur. Color change is not the only consequence of exposure to light. Textile fibers also become weak and brittle through exposure, and the effects of this deterioration are permanent, and cumulative. The range of the spectrum of light that you should concern yourself with includes ultraviolet, visible light and infrared from natural and artificial light sources. Incandescent lights seem to have an acceptable level of ultraviolet radiation, although these lights do produce infrared radiation (heat), which accelerates chemical reactions, such as the embrittlement of fibers. The location of this light source is important. It must not be too close to the tapestry. Briefly, the guidelines that you should try to attain are the following:
- avoid placing textiles in direct sunlight
- use ultraviolet filtering films on windows (http://www.gilafilms.com/en/Energy-Saving-Window-Film.aspx) or energy efficient lowE windows
- avoid fluorescent lighting or use ultraviolet filters on lamps
- note placement of artificial light sources and relocate bulbs if there is a heat build-up close to the textile.
The placement of the tapestries is optimal in the space but the windows should have some UV protection (film) placed on the windows if not already present. This should protect the fiber piece from about 98% of the UV. Not illuminating any spotlights will also help in decreasing the damage to the piece. I do not feel that the textile will need any illumination other that what is already naturally present in the room, but if needed an easy and acceptable solution is to make sure that you use ultraviolet filers on the lamps.
High temperatures, excessive heat, and high humidity can also accelerate the deterioration of textiles and provide a desirable climate for insects, mold and mildew. If mold and mildew are caught early enough, before staining has set, the textile can be removed and a textile conservator contacted immediately. Ideally, a climate of 65-70°F and 50-55% relative humidity is best. However, the maintenance of an environment with as little fluctuation as possible is important. The mold and insect (moth) problem has also been buffered since the piece hangs away from the wall. This increases air circulation and light. Moths and mold generally like a dark moist environment. By placing the textile away from the wall the “hidden” area is decreased. Also by backing the textile with canvas the insect damage is lessened. Moths like to hide on the underside (floor or wall) of a textile and feed on the wool fibers from the back. By backing the piece in a cotton canvas it prohibits them from immediate direct contact with the wool fibers. Also, any accumulated moisture from the space in between the wall and textile will evaporate faster with cotton than wool.
Although air pollution is an enemy of textiles, dirt and dust will probably be the greatest problem with this piece. Dust particles act like small knives, cutting into fibers as the textiles expand and contract in response to changes in relative humidity. A regular schedule of inspection and vacuuming is generally recommended to maintain the fiber piece. I do not agree with anyone other than a conservator, vacuuming a textile. Improperly vacuuming a textile, rather than leaving the dirt untouched, generally causes more damage. The textile should be checked for dirt and insects during the regular servicing of lights. I don’t feel that the piece will need vacuuming for at least five to ten years but that will be determined on the level of dirt and dust in the area. If there is damage or if the tapestry is excessively dirty then it should be cleaned by a textile conservator. Never have the tapestry cleaned by a dry cleaner. The chemicals used by a dry cleaner can damage the color of the tapestry and degrade the wool.