How to Define Components as “Core” or “Finish”
For composite elements (Wall, Slab, Roof, Shell): skins can be defined as either Core, Finish, or Other in the Composite Structures Dialog Box. You can define multiple skins as Core, but these skins must be adjacent to each other.
You can define multiple adjacent skins as Finish, but they must include one or both of the outermost skins.
For Profile elements (Wall, Beam, Column): Components can be defined as Core, Finish, or Other in Design > Profile Manager.