Insensitive restoration has caused many paintings to be irreversibly damaged. A painting is a sculptural relief; it is not two dimensional. In the 19th century excessive pressure was used to repair tears an-d line canvases, resulting in flattened surfaces and thus distorting the original appearance of the work. Good conservation maintains the intention of the artist. This requires a knowledge of art history and science: knowing the materials and techniques used by certain artists and how they change with age, studying paintings still in mint condition, unfinished paintings (which can cast light on drawing, modelling and glazing techniques), and the diaries and notes of historic artists. The conservator must also undertake scientific analysis of paint and ground layers, x-radiography, infrared photography and other sophisticated procedures. Article briefly cites the three graduate training programs in conservation in the United States. Includes basic bibliography in paintings conservation. -- AATA