A copy of a work of art that is virtually indistinguishable from the original. Unlike a fake, a replica is not trying to pass for the original and is often made by the artist and used for historical and educational purposes. The vogue for collecting replicas reached the height of popularity in the mid to late nineteenth century when few people could afford to travel on the Continent, so museums acquired reproductions of important monuments and works of art to complement their collections. Replicas in modern art are made as a result of original works of art decaying or being lost. Marcel Duchamp's Fountain, the most famous of the artist's readymade sculptures, was replicated in collaboration with Duchamp from a photograph of the lost original. Tate holds the largest collection of plastic sculptures by Naum Gabo, but despite controlled storage conditions, many of these works are cracking and warping. Computer software will be used to help virtually restore the sculpture models, so that replicas can be made of the originals.