Albumen prints from the 19th century are prone to fading and yellowing. A study by James Reilly (see <i>AATA</i> <b>19-1923</b>) indicated that high relative humidity, not fading, has been responsible for the deterioration; alkaline storage materials accelerated the yellowing while acidic storage materials produced fading. Storage conditions of the photographs are to be monitored. See also <b>20-1254</b> for information on taking humidity measurements.