Small packets containing water-absorbent materials, such as silica gel or clay, are frequently employed to control humidity levels in enclosed spaces where volumes are stored. These materials adsorb and hold moisture from the surrounding air, mitigating the risk of damage from mold, mildew, and other humidity-related deterioration. A common example is their inclusion in shoe boxes to prevent moisture damage during shipping and storage.
Preserving valuable literary collections often necessitates humidity control. Excessive moisture can lead to foxing (reddish-brown spots), warping, and the degradation of paper and bindings. Using these moisture-absorbing packets within storage containers provides a cost-effective and relatively simple method of safeguarding these items from such damage. This practice has become increasingly common, especially for rare books, archival materials, and those stored in less-than-ideal environments. Historically, libraries and archives have utilized various methods to control humidity, ranging from environmental controls within the entire storage area to the inclusion of simple, readily available absorbent materials.
