With the exception of adjustment layers, any layer can be designated as a 3D layer. When a layer becomes three-dimensional, it acquires additional transform properties as well as “material” properties exclusive to 3D layers (Figure 16.1). (See “Using 3D Orientation and Rotation,” “Using 3D Position,” and “Using 3D Material Options,” later in this chapter.) By default, 3D layers are positioned at a Z coordinate of 0.