Discusses the often conflicting conservation needs of composite objects, and the so-called inherent vice that results from the different physical and chemical properties of the materials that constitute these objects. Presents generally applicable guidelines regarding climate, lighting, and the prevention and treatment of insect and rodent damage. Tables list examples of organic and inorganic materials found in historic, ethnographic, and fine art collections; the objects are then divided into those sensitive to high and low relative humidity, and insect and rodent infestation. Appropriate recommendations follow. A table of reactive materials shows the conservation problems their combination causes.