You’re probably used to finding packets of silica gel in your shoes boxes, electronic packaging, new purses — its uses are many — but did you know it’s also hidden in spots all around galleries and museums? In this post, conservator of sculpture and decorative arts Lisa Ellis explains why it is also a simple but powerful material used in the preservation of artworks.
Silica gel is a key aspect of preventive conservation at the AGO. Silica gel packets and sheets are hidden inside display cases and behind paintings to keep humidity levels stable. This is essential, because fluctuations in humidity levels may cause canvases to shrink and stretch and high humidity levels encourage corrosion of metals. While the AGO has a very sophisticated system for controlling the heating, cooling and relative humidity in exhibition areas, sudden changes in the temperature outdoors or even a large group of visitors may temporarily affect the humidity in an exhibition gallery.
Silica gel used at the AGO is a porous and hygroscopic material that has been preconditioned to a set humidity, typically 45 per cent. When the humidity in the environment surrounding the silica gel increases, the silica gel absorbs moisture and, conversely, when the air dries moisture is released by the silica gel. The silica gel very effectively smooths out highs and lows, keeping artworks safe in a stable environment.
For further information, please see this definition of silica gel.
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