When an object reaches the Field Museum it has often lasted longer than its intended life and may be in a fragile or worn condition - repairs or stabilization of damage may be important to prevent further deterioration of the object. Some objects, such as archaeological pottery, typically arrive at the museum broken and may need to be reassembled from fragments. Treatment of a museum object to repair damage, improve physical stability, or to restore appearance or function, is a delicate and potentially costly business: treatment time for an object can very from hours to months and conservators are mindful that treatment always involves some risk of damage or alteration of original properties.
The ideal is always to preserve the original object so far as possible. Where possible, the cultural functioning of an object is considered as an integral part of its properties, as worthy of preservation as its physical form.
Many modern adhesives and consolidants have short service lifetimes (five-ten years) and change color, weaken, or insolubilize as they age. Restoration materials are selected for their long-term stability and reversibility so that, if a treatment is learnt to be undesirable in the future, it can be undone. Where possible, materials which can be distinguished from the original materials of construction are used.
Each stage of a treatment, the materials involved, and its outcome must be documented so that researchers in the future can distinguish between work done now and the original object as collected into the museum.