Utilizing short-term (5-week) laboratory exposures under conditions of high relative humidity, samples of polymers and resins important in preserving art materials, particularly stone, were evaluated for their ability to support fungal growth. Growth of the organisms was ascertained by macroscopic, microscopic, and physico-chemical changes of these materials over a 5-week testing period. Based upon their sensitivity to fungal deterioration, the polymers and resins tested were quantitatively ranked in order of least to most susceptible to biological attack.