The dual ideas of education and preservation have motivated museums to acquire not only the best examples of objects for permanent display, but also other examples to explain the range and development of a particular form of object. Museums usually choose to display the best examples of the objects they have acquired and some additional examples to show variations. Owing to space limitations, many other objects remain in storage and are made available to scholars and collectors for further study. Museums usually try to rotate objects on display to reveal the extent of their holdings and to add variety for returning visitors. Objects from storage (and sometimes those on permanent display) are frequently made available to other institutions as short-term loans for traveling exhibitions.
The Museum's collections have been built over the years by means of gifts and purchases of individual objects and, sometimes, of whole collections. Trustees and curators have eagerly sought certain objects, such as the Museum's collections of watercolors by John Singer Sargent and Winslow Homer. An object might be purchased to fill a gap in the collection, to better explain the evolution of another object, or to document another phase of an artist's career. An object might also be acquired, rather than borrowed, for a special exhibition.
Since the Brooklyn Museum is an art museum - as opposed to a historical society, ethnographic museum, natural history museum, or museum of technology - assembling a comprehensive selection of objects of high aesthetic quality is the foremost consideration guiding acquisitions. Many additional factors might determine why an object is acquired. If an object was made in Brooklyn, retailed in Brooklyn, or owned by a prominent Brooklynite, for example, and meets our museum's aesthetic criteria, it might be considered for acquisition. As collecting priorities, interests, scholarship, and current institutional values are redefined, museums not only acquire objects, but also regularly review their collections and deaccession works of art, or officially remove them from the collection, and then sell them at auction or transfer them to another institution.
When starting to plan an exhibition, curators decide what stories they wish to tell in the galleries. This decision affects the selection of works of art and the organization of the display. Sometimes a story is better told if the objects are shown chronologically, and sometimes geographically. At other times, curators decide to exhibit objects in a more thematic way, as in the adjacent American Identities installation. Curators are always eager to put a recent acquisition on display; and if the Museum receives an important collection of objects, the group might be placed on display for a period of time before being incorporated into existing installations. Some objects, such as works on paper, textiles, and photographs, are limited in the amount of time they can be on exhibition owing to the inherent fragility of their media. Fragile objects are therefore rotated back into storage and replaced with similar objects from storage.
The Museum has a full-time staff of conservators who are in charge of the condition of objects in the collection. Conservators routinely examine potential purchases and gifts prior to acquisition to ascertain the condition of objects. If an object is deemed too fragile or overly repaired, for example, the decision may be not to acquire it. Some objects change over time and require treatment. Silver, for example, will tarnish and must be periodically polished to show at its best. Conservation decisions require balanced judgments regarding the appropriate level of treatment. Some objects traditionally are presented with a higher level of conservation than others. French eighteenth-century furniture, for example, is almost always more highly conserved than American furniture of the same period. A basic tenet of conservation treatments is that they should be reversible so that future generations will have the option to make a change if new information about the appearance of the object is discovered or better materials for treatment become available. In addition to caring for and preserving works of art, conservators collaborate with curators to investigate an object's original appearance and history of alterations, using technology such as X-radiography and infrared light as well as examination with the naked eye.