You can create materials that consist of multiple layers of maps and/or operations (tint or gamma setting). You can define the way that the maps are blended and you can assign a value for opacity, to allow one map to be seen through another.

You can create more complex materials by adding layers of pattern maps. For example, you can create a brick wall that includes one or more signs, as shown below.

Multi-layered material example

You can create this type of material by assigning a pattern map for the wall, and then adding layers for the overlayed pattern maps of the signs. The patterns for the signs have Repeat turned off and offsets defined to position them on the wall.