Sculpture
Sculpture is the art or practice of shaping figures or design in the round or in relief, as by chiseling stone, or modeling clay. Traditional materials used for the making sculptures are stone, metal, wood, ivory, bone and clay. Sculpture may be either in the round or in relief. A sculpture in the round is a separate, detached object in its own right, leading the same kind of independent existence in space as a human body or a chair. A relief does not have this kind of independence. It projects from and is attached to or is an integral part of something else that serves either as a background against which it is set or a matrix from which it emerges. In technical words Round sculptures has three dimensions whereas Relief sculptures has two dimensions. But in high relief sculptures, sculptor tries to give third dimension to his picture but never completes the third dimension. Thus high relief sculptures gives effect of three dimensional pictures.

Round Sculpture
Round Sculptures, since the 20th century has not been confined to the two traditional forming processes of carving and modeling or to such traditional natural materials as stone, metal, wood, ivory, bone, and clay. Because present-day sculptors for making Round Sculptures use any materials and methods of manufacture that will serve their purposes, The art of Round sculpture can no longer be identified with any special materials or techniques.

But about the Relief Sculptures, for a sculptor ( not machine ), method of carving and material used has remained same as traditional method and material.

Relief Sculpture
A type of sculpture in which form projects from a background is called Relief Sculpture. Relief Sculptures out of stone, wood ivory and bone are made only by the chiseling process. But since metal is a only material which is available in solid log or in thin sheet, Relief Sculptures of metal can be made by carving as well as by embossing process.

Types of Relief Sculptures
There are three degrees or types of relief: high, low, and sunken. In High Relief, the forms stand far out from the background. In Low Relief, ( best known as Bas-Relief ), they are shallow. In Sunken Relief, also called hollow or Intaglio, the backgrounds are not cut back and the points in highest relief are level with the original surface of the material being carved. Sunken Relief can be more explained as, where the image is carved into the material, creating an effect of negative, in contrast to other types of relief work where the surrounding material is carved away to leave image.

Metal Relief Sculpture ( Also called Repousse )
Since the metal is a only material which is available in solid log or in thin sheet, Relief Sculptures of metal can be made by carving as well as by embossing process. Carving is the process of removing material with the help of chisel and hammer to bring that material to desired shape or figure. Embossing means raising the surface to the desired form or shape. If the metal is a solid log, embossing is done with the help of carved die made up of comparatively harder metal and by giving large pressure on that die over the log of metal, so that the background compressed for depth. For example : coins are made by emboss process. If the metal is a thin sheet, hard enough to push or press, metal relief or embossing is done by punching process using two traditional tools : punch and hammer. If the metal is a very thin sheet soft enough to push or press, metal relief or embossing is done just by hand pressing using Teflon or wooden tools.

Relief Sculptures made up of metal and made to display on wall are also called metal wall sculptures.

For metal relief works, the metal should posses two main qualities like softness and malleable ness. And these qualities are found in maximum proportion in Gold metal, thereafter in Silver, Copper and Aluminum.

Metal Wall Sculptures by Anand Charya
My metal wall sculptures are the relief sculptures made by the embossing process. In my metal wall sculptures I have chosen Aluminum metal since it is much cheaper than the gold and silver. My metal wall sculptures are done by stretching the metal down into a mould of soft supporting pith ( mixture of plaster of Paris, wax, tar and linseed oil ). Relief is made by keeping the metal sheet on the pitch and then by hammering the metal into the pitch. The pitch supports the surrounding metal while metal being relief or raised or embossed. Hardness of the pitch is kept as per the depth of the metal desired. For detail work use of wooden mould is also done. Punches of various sizes and shapes are used according to the depth and width of the embossed shape. Sizes of my wall sculptures are : 2 ft. x ft. and 3 ft. x 2ft. I have achieved the depth of 2 to 5 inches in my works. Central form of the pictures are colored with transparent colors to maintain the metal sheen and opaque colors are used over background. Besides, every creation is exclusive.

Use of Sculptures
In ancient time, Religious kings and saints used wall sculptures to give message of conduct for the people for the peace and goodwill of the society and humankind. Some kings used wall sculptures to show his strength to the world. Sculptures in the form of statues are made to remember one's personality. But mostly, Sculptures are often used in architecture to decorate buildings, walls, etc. because wall sculptures always give a noble touch to that place. It shows prosperity of that place.