Some of the more advanced imitators have somewhat obviated this difference of dimension by mechanical methods of expanding moulds, but the work in such cases is not so perfect as otherwise and what is gained on the one hand, namely, a dimension identical to that of the original, is lost on the other, as methods of taking over-sized moulds from originals are generally imperfect. A flourishing product of the Italian market are bas-reliefs and clay busts in imitation of Renaissance work. When not the work of clever artists who model direct from the clay, having studied and mastered the old style, it is the product of miserable mechanical deception aided by ability to disguise its patchwork nature, the trickery and general sleight-of-hand of the wily art of faking. In the case of bas-reliefs they are often composed of different parts belonging to different originals, sometimes originals unknown to connoisseurs and art critics. This method has been applied to the imitation of Renaissance terra-cotta busts. A bust bought at a high figure from a Venetian antiquary many years ago and believed to be genuine Quattrocento work was afterwards discovered to have been made from the cast taken from the face of a recumbent figure on a tomb in the church of San Pietro e Paolo, to which had been added the back part of another bust, the whole finally set upon a pair of shoulders cast from another original of the period. The monument from which the face had been moulded was so high up on the wall of the church of San Pietro e Paolo that no one knew of the existence of this original and the other parts of the faked object had also been taken from little known originals. The fraud was discovered in Paris some time after the bust had entered a noted collection, a lawsuit ensued and the collector eventually recovered the money he had paid.