What are the principal techniques of sculpture?

There are many techniques used to make sculptures. They are, modeling, casting, carving, construction and assembling (Frank, 2013, p.190).  In the modeling technique, wax, clay or plaster is used. How it works is one of these material is first built up in the size the artist wants his/her sculpture to be. Then gradually pieces by pieces, part of the build are separated until the final sculpture is left. In the casting technique, a sculpture of clay is made and then it is filled with another hard material. When the clay structure is broken, the sculpture made up of hard material is left. In the carving technique, a wood, stone or other material is carved to make a sculpture. In the construction and assembly technique, iron, wood, or any other material is used to construct an art work. Different parts made up of these materials are combined together to assemble a sculpture.