Replication, or making exact copies with consistent results, is at the heart of manufacturing. It is used in mass production of all kinds of items, from foodstuff to cars, from houses to books. But it is also used to reproduce already existing objects. In the 18^th and 19^th centuries plaster casting was used to bring the wonders of the world to private collections and museums. In the cast court of the Victoria and Albert Museum in London, a life sized replica of Trajan's column [1] can be admired. The combination of a 3D scanner and printer offers the possibility of a new way to make a three dimensional copy of an existing object. Whereas in a plaster cast, where high fidelity is achieved by creating a physical mould from the original object, scanning does not require physical contact to the original. This can be an advantage when the object is fragile, but can lead to loss of fidelity during the reproduction process. We discuss the difficulties in achieving a truly high fidelity copy of even simple objects when a scanner and 3D printer are used for object replication.