Art conservators typically have, at minimum, a master's degree in art conservation. Their academic training includes art history as well as scientific and historical aspects and requirements of pieces. Fine art conservation developed after World War II, but art restoration spans history and very likely dates to the beginning of art creation itself. An art restorer was typically a trained artist herself, usually an artist's apprentice.
Conservationists seek to preserve cultural property for the future. Conservationists examine, document, treat and prevent damage and wear on artwork using research and educational background. Museums conserve art so it will be available to future generations. Conservationists stress the importance of understanding the piece's materials thoroughly to ensure it will last. Restoration returns works to their original condition. This may include adding elements that weren't originally part of the piece, but resemble it. Restorers may aim to keep all amendments to an original work reversible, but this varies between crafters.
Conservation entails preventative care as well as repairs. Preventative conservation includes routine inspection and maintenance, placing a piece in a controlled climate, ongoing education on preventing damage and handling and on traveling objects and documentation for insurance, asset management and disaster plans. Restoration typically focuses on one individual issue or a specific set of issues. A restorer may focus on studying a hole in a canvas under a microscope, and then reattach the torn ends by patching a piece of canvas on the back or weaving the canvas fibers back together. A restorer may also tighten up distended segments of a canvas' weave caused by humidity and perform other repairs.
Art historians debate how much restoration is enough or too much. They must weigh whether strictly adhering to the artist's original intent is more important than conserving or restoring the object and how they will preserve an object if it's experienced natural breakdown of the material. For instance, bronze surfaces experience oxidation leading to patina, a greenish film covering the surface. Some historians argue that removing patina removes part of the piece itself. Restorers also risk removing some of the artist's original varnish, as in a restoration of the Sistine chapel that left the images much brighter than some believe Michelangelo intended.