Wood carving is a form of working wood by means of a cutting tool (knife) in one hand or a chisel by two hands or with one hand on a chisel and one hand on a mallet, resulting in a wooden figure or figurine, or in the sculptural ornamentation of a wooden object. The phrase may also refer to the finished product, from individual sculptures to hand-worked mouldings composing part of a tracery. The making of sculpture in wood has been extremely widely practiced but survives much less well than the other main materials such as stone and bronze, as it is vulnerable to decay, insect damage, and fire. It therefore forms an important hidden element in the art history of many cultures. Outdoor wood sculptures do not last long in most parts of the world, so that we have little idea how the totem pole tradition developed. Many of the most important sculptures of China and Japan in particular are in wood, and the great majority of African sculpture and that of Oceania and other regions. Wood is light and can take very fine detail so it is highly suitable for masks and other sculpture intended to be worn or carried. It is also much easier to work than stone. Some of the finest extant examples of early European wood carving are from the Middle Ages in Germany, Russia, Italy and France, where the typical themes of that era were Christian iconography. In England, many complete examples remain from the 16th and 17th century, where oak was the preferred medium.