Prospective students of Greek sculpture are daunted by the fact that they have to tackle a bibliography in several languages that stretches back to the 19th century and must often employ methods that are deemed old-fashioned. The development of style is, nevertheless, giving way now to the study of materials and techniques, as well as the historical perspectives underlying the production of sculpture at any given period. An additional difficulty is the fact that new material that comes to light is not always easily available for study, and even old material can remain out of bounds due to bureaucratic barriers. Current research tends to concentrate on the detection of polychromy on marble sculptures, a process which is best undertaken in the conservation departments of museums. 3D scanning is another expensive method which is currently being developed in various research directions.