Sculpture is the creation of three-dimensional forms. A form is an object defined by contour, height, depth, and width. Sculpture is created through three basic processes: carving, modeling, and assembly.
Carving: The sculptor removes unwanted material to create the form. This is also called subtractive sculpture. Generally, materials such as a block of wood, stone, and other hard materials are used.
Modeling: The sculptor creates a form by building it up from an amorphous lump of plastic material.This is also called additive sculpture. Clay, paper machê, and other pliable materials are modeled into a sculpture. Modeling with clay is generally the first process for creating a cast metal sculpture.
Assembly (or construction): The sculptor joins prefabricated elements as in welded metal constructions. This is also additive sculpture. Materials such as steel, wood, and found materials are glued, welded, or connected in some other fashion to create a sculpture.