The chief cause for decay in textiles is almost always the environment in which they are stored. Light, temperature, and humidity can all contribute to a textile's health or deterioration, depending on their intensity. Additionally, pests, chemicals, and pollutants may also cause damage to an antique fabric. Airborne chemicals, such as smog or cigarette smoke are also harmful to the textiles, and should be avoided if at all possible. In museum or otherwise specialist collections, high-efficiency air filters are typically installed throughout the building to reduce the presence of airborne chemicals that may stain, discolor, or weaken fabrics.
Light Light can have a variety of effects on textiles over time. In some cases, it may contribute to fading or discoloration, but the primary damage caused to textiles by light is fiber weakness caused by prolonged exposure to
ultraviolet and
infrared lighting. Ideally, textiles should be stored or displayed in as little light as possible, and preferably in total darkness. However, as this is impractical for display and care of the piece, knowledge of UV exposure limits and how a textile can be handled under safe amounts of lighting are also necessary for conservation.
Natural light is the most common source of ultraviolet light, and as such, care should be taken to avoid exposure to direct sunlight at all costs, and indirect sunlight whenever possible. This may mean storing or displaying textiles in an area without windows, or with blackout curtains, which can be drawn whenever the room is not in use. If a room relies on natural light, UV screens or coatings can be applied to the windows to block harmful rays while still allowing light to pass through. These filters should be checked periodically, however, as they have a limited lifespan and may need to be replaced every few years.
Fluorescent and halogen-produced light can also produce large amounts of UV radiation, though filters which fit over the bulbs are available to limit the damaging light. These filters are typically replaced when the bulbs are changed. One advantage of fluorescent lights is that they produce little
heat, which may also be harmful to textiles.
Incandescent lights produce a large amount of heat in addition to large quantities of infrared radiation, which is likewise damaging to the fibers in antique textiles. If incandescent lights must be used, they should be placed far enough away from display cases that their heat does not affect the contents. In the case of particularly delicate textiles, display organizers might consider
motion-activated or timed lighting, or lighting controlled though a visitor-activated switch, which would allow the textiles to remain in darkness when not under view. All textiles should be displayed on a rotating schedule, allowing them a few months of display, then the rest of the year in dark storage, to prolong their life.
Climate Victorian altar frontal,
Berkshire, England Heat and
humidity can both contribute and a textile's deterioration. However, excessive dryness may also cause damage, especially to elastic fibers, such as
wool, which rely on some amount of
moisture to maintain their flexibility (Putnam and Finch). Additionally,
temperature and humidity should be kept as constant as possible; changes in either of these may cause the textile fibers to expand and contract, which, over time, can also cause damage and deterioration to the textile. For this reason, both storage and display areas should be fitted with
monitoring equipment to gauge the temperature and humidity of rooms, display cases, enclosed storage facilities, and work areas. Ideally, temperature should be kept around , though some slight fluctuation in either direction is permissible, as long as it occurs gradually. For instance, temperature may be slightly lower in winter to save energy costs, but the change should be effected slowly, so as not to place the fibers under undue stress. As for humidity, the preservationist or conservator should aim for a relative humidity of 50%, though, as with temperature, some small fluctuation is allowable, as long as it occurs gradually. In enclosed display or storage cases, humidity can be somewhat maintained through the use of
silica gel crystals. These crystals should not be placed in contact with the textiles, but may be placed in breathable muslin bags and hung inside the case to maintain a constant humidity; In addition to temperature and humidity, airflow is also a concern for textile preservation. Textiles should never be sealed in plastic or other air-tight casing unless it is part of a treatment or cleaning process. Proper circulation, combined with the suggested humidity, will help to prevent the growth of
mold and
mildew, which may
stain or weaken antique textiles.
Pests Pests are another significant threat to textile collections, as there are a number of creatures that can cause damage to fibres. Among the most common are
clothes moths,
carpet beetles,
silverfish,
firebrats and rodents. Clothes moths are attracted to
protein fibres, and so are especially drawn to
silk, wool, and
feathers. An infestation might be identified through the evidence of white
cocoons (or the remnants thereof) on the textiles, or of sighting the insects themselves. They are roughly long and white in colour. In the case of a rodent infestation, all access points to the room (such as cracks or holes) through which they might be entering should also be located and sealed if possible. For
insects, keeping clean storage, display, and work environment is the best method of prevention. Sticky
traps (replaced often) around doors, windows, and display cases may be useful for monitoring the insect population. Furthermore, the population of carnivorous insects, such as
spiders, should be observed. While such insects are not harmful to textiles by themselves, they may indicate another population of insects which are. If the infestation can be limited to one or a few pieces, the insects may be killed through
freezing of the object. The textile should be wrapped in plastic and
vacuum-sealed, then brought to a freezing temperature as quickly as possible, to prevent the insects from adjusting to the cold. The object may be left frozen for several days but should be brought slowly back up to room temperature to avoid further damage. While this method should kill adults, it may not destroy any eggs that are present. If chemical means must be employed, it would be best to consult with a professional conservator to be certain that the treatment will not harm the textiles themselves. Even if no signs of an infestation are present, textiles should still be inspected periodically to be certain that there is no outbreak that has gone unobserved. Additionally, when dealing with a new acquisition that shows signs of insect damage, the specimen should be
quarantined until it can be determined whether the insects are still present before introducing it to the rest of the collection. ==Textile instability==