AM makes both multi-material and composite parts. A multi-material part consists of many materials, which does not inform how one material influences another. A composite consists of multiple materials or one material of different types. As a multi-material part, its property and function are due to the combination of materials. If it consists of two materials, one material influences another, which gives rise to a combined property. The individual property of each material is no longer applied when it is used in applications. This is the difference between a composite and a non-composite multi-material part. For example, for a multi-material part as a transition part in a furnace wall, one side of the part is made of ceramic to face high temperature inside the furnace, and another side is made of plastic to face room temperature outside the furnace. Thus, ceramic uses its individual property when used inside the furnace, while plastic uses its individual property outside the furnace. The transition part is not intended to consist of ceramic and plastic in such a way that they will give a combined property and not show their individual property when applied. In the application (furnace), it is the individual property of a material that provides functionality. Thus, in the transition part, there are two materials, two individual properties, and two functions.