Climate

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 70 degrees Fahrenheit ^[6], though some slight fluctuation in either direction is permissible, as long as it occurs gradually ^[7]. For instance, temperature may be slightly lower in winter to save energy costs, but the change should be affected 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 (Mailand). 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 ^[7]; they should be monitored periodically, however, to be sure that they are working.

In areas where climate control is unavailable (such as in historic buildings), the conservator can still moderate the temperature and relative humidity through use of fans, humidifiers and dehumidifiers, and portable heating or cooling units ^[8].

In addition to temperature and humidity, air flow 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 ^[9]