Background patterns are restricted to which type of patterns?

Background patterns in Revit are specifically utilized in drafting views, which makes them restricted to drafting patterns. These patterns, often used for conceptual representation in drawings, help convey information such as materials or textures on a plan or section view without representing the actual material properties in the model itself.

Drafting patterns are ideal for 2D representation and are applied on sheets, making them effective for detailing and documentation purposes. They allow architects and designers to create visual distinctions in their drawings, aiding in clarity and communication of design intent.

In contrast, model patterns are applied directly to elements in the 3D model and represent physical materials. Composite patterns are used in advanced applications, often associated with composite structural materials. The option indicating that no patterns are allowed does not apply since drafting patterns are indeed permitted for use.