n.a condition in which material is discolored, darkening from a neutral white shade to shades ranging from cream to brownLathrop 1980, 330The U.S. government specifies that the drafting films it purchases must not incur an increase in opacity (yellowing) of more than 5 percent after an accelerated aging test in which the material is heated at 212 degrees F. for ten hours.O’Connor 1984, 162Improper lighting presents a serious threat to exhibited documents. Both paper and ink undergo photochemical changes such as yellowing, fading, and accelerated physical deterioration when subjected to light; and light damage is irreversible.Cocciolo 2016, 134Some archivists would prefer not to assign item-level metadata to large volumes of digital assets, just as some digital asset managers would rather not steward troves of yellowing papers.Harvey and Mahard 2020, 156Wood-pulp papers of the late 19th and 20th centuries are susceptible to yellowing and brittleness because of their lignin content.Harvey and Mahard 2020, 193Maintaining stable temperature is less critical than maintaining stable humidity control. Nevertheless, keep in mind that higher temperatures speed chemical reactions such as fading and yellowing.
