Fabric is a property of the MATERIAL (direction + aniso strength), not the layer. Layers place one material per shell; each domain warps its patch by that material's fabric (concentric→rings, foliated→grain, radial→spokes, else isotropic). Fault roughness bends the domain boundaries into natural seams — applied to the boundaries before cells are cut, so it stays watertight. Domain seams = major faults; cell borders = minor joints.